Here’s the list of products reviewed. More details in the video description. Thank you! TIME SERT: amzn.to/3OZvmUj Heli Coil: amzn.to/3NASSG1 Loctite Threadlocker Red: amzn.to/3NGoBFR Loctite Stripped Thread Repair Epoxy: amzn.to/3R8aFr1 JB Weld: amzn.to/3yC1ND2 E-Z LOK: amzn.to/3upNL4P HHIP: amzn.to/3yxZkbo
I liked the testing methodology especially because you used aluminum, however, It would be great if you retested the high performers with a better grade bolt. That way you are testing the strength of insert not just the bolt failing.
Not only do I appreciate the effort to make all the tests and comparisons of the thread repairs, I salute your ability to drill and tap ALL those test pieces. There is a LOT of work involved in these videos that don't even add to the video content, or barely so
His testing is invaluable, especially for a DIYer like me. Before I try anything I haven't used before, the first thing I do is see if he has done something on it. The time and effort that must go into these is mind boggling.
Just about to move into my new house as a first time home owner and I have referenced your videos so much. The recommendations you give are one of the few I trust and I couldn't be happier with what I've bought. Thank you for your unbiased and logical approach as usual and I hope you enjoy making these as much as I like watching! EDIT: Holy cow! Thank you so much everyone for the well wishing! I am laid up with an ankle injury that happened this past weekend and am surrounded by all of my boxes of unpacked stuff, I wish there was a gadget to help me now 😆 but I am about to go out and enjoy a bit of birthday fun with my good friends and I will get back to unpacking after a few days rest. Thank you all again, I genuinely appreciate so much well wishing, my little house feels even more of a gift now.
I started to buy my tools based on his recommendation. Witch is hard, since not all brands are available in Romania… but now at least I know what to look at… specially when the seller is telling me a lot of marketing bullst… and I’m like We’re going to test that 😂😂
Is it a new house or new to you? On a new house, or new cabinets, go through and try to tighten all the cabinet door hinges. My bet is that you'll find at least one, if not several stripped ones. I think this is due to the screws being small and the people at the cabinet factory being in a hurry with power drivers. Repair is a similar concept to this video, except you drill out the hole with a 3/16" bit, glue in a piece of 3/16" dowel, then redrill the hole and reinstall the hinge. Ask me how I know this.
I learned about helicoils while working on jet skis back in the mid 2000s. The German operated shop had some pretty genius solutions to repairs, and jet skis plus salt water meant we had our hands full with bolts, threads and the failures from both. But one day when I thought we were totally out of luck, out came the helicoil kit and it blew my mind on how easy and solid the repairs were. I have recommended helicoil repairs multiple times over the years yet nobody seems to know that type of repair is an option, and that the average person can make a repair in minutes that would normally have to go to a machine shop. So as always, thank you for the fantastic video, but also, thanks for spreading the knowledge of these types of tools and how easy it can be to do this. Year after year, manufacturers make it harder and more complicated to repair your own items. Tools like this out the power back in our hands and keeps money in our pockets.
So many people discount helicoils. Being highly corrosion resistant, inexpensive, and easy to install, they are my go to for jet skis and automotive thread repair 🤙🤙
i learned about helicoils in Auto shop back in the late 80's, i had stripped a thread on a Holley fuel bowl screw trying to tighten it to get it to quite leaking gas. the teacher showed me how to take the carb completely apart and put it in the drill press, line everything up and drill it for a helicoil. I have been using them ever since, and i still hate leaky Holley carbs to this day.
@@shadvan9494 lol. I have a Holley I just rebuilt for my 72 f100 and it leaked all over. Had a spare Edelbrock I tossed on her, but battery is dead do I don't know if that one leaks too lol
Something interesting about threaded inserts is that for space hardware (which I work on), we use these as standard when threading in to softer materials like magnesium or aluminum. As you saw, it makes things stronger!
I'm guessing that, since the aluminium remains the limiting material, they're stronger simply because of the slightly larger threaded aluminium hole having more thread overall, combined with a courser thread? So the strongest solution would be the one with the largest outer diameter and a course thread?
@@bakedbeings I would imagine that the insert would exceed the bolt of the same size as the steel insert would expand against the aluminum as the bolt pulls against the insert. Kind of like a climbing expander.
13:49 Pro tip for everyone: If you send aluminium parts for anodizing, insert the Helicoils AFTER the anodizing process. This one time I had to drill, tap, and insert some 500 Helicoils into pieces a coworker messed up (never checked his threads), and when they returned from anodizing, all Helicoils were gone. Whatever acid bath they used to clean the parts, it had no problem dissolving the Helicoils.
Anodizing means that you are turning the part into an anode. Both stainless steel and aluminum work because they form an oxide so quickly that it forms a skin that protects the metal underneath. That means that if you scratch through it or prevent it from happening the part can be eaten up. That's why they will use a process to build up the thickness of that skin. With a conductive material instead of only getting heat when atoms combine you can also get electrical current. As in you can kinda think of rust being like fire since at some point if it happens you see flame but matter just has some basic ways it works so depending on how you add electricity to metals you can get reactions and with anodizing you are forcing it to react. If you mix metals they will make a battery and there is a scale of nobility if metals showing how much they react. Steel and aluminum aren't that bad normally but in an anodizing tank they will react. By having those inserts in there you probably had some minor changes to the oxide layer since it had to eat the steel before it would begin to work on the aluminum. You might also find it interesting that aluminums oxide layer unlike the chromium oxide layer tends to be a bit more open and thicker and is what makes aluminum special because it's really hard your average sandpaper that will cut even very hard steel is aluminum oxide. It's why it makes great boats since you have a soft tough inner material with an ultra hard exterior that self heals and doesn't wear much when you run it on shore. Some metals when you anodize or form colored oxide layers on them change the surface pattern so they reflect light different like a peacock feather but aluminum is different and they put dye in the mix that gets trapped into the skin. It just accurred to me that thermite is iron oxide and aluminum. Aluminum is extremely reactive and I don't know all the chemistry but once you get it hot enough it can actually pull the oxygen from the iron basically just pure rust to itself and burn it. It's not as reactive as magnesium but it's up there and can be used in explosives as well. A safety note is to not mix them when grinding at least on a large scale.
I used to work at a shop and we had that problem too... A couple whoopsies with batches of parts helicoiled before treating. They'd come back all blackened and stained and we had to redo the parts. Always fun redoing stuff in an absolute rush...
Want to remove steel bits from am aluminum part? Immerse it in a saturated alum solution. It will dissolve the steel out without touching the aluminum. Be patient…
47 different holes painstakingly drilled, tapped, cleaned. This is an insane amount of work, like all your other videos, to test these things. I'm off to patreon to thank you in other ways as well, but man... thank you for all this!
I appreciate this channel and work he is making for the videos but... Because of my work, once a while I mark and drill holes into aluminium. Some days can be 500 plus holes...
I used a cheap eBay helicoil clone kit for holding my front axle clamp on my dirt bike. I was really nervous to push it with the repair, but it's been holding well for over two years. Your results make me even more confident!
Yes even the cheap kits are stronger than the parent metal, especially in aluminium alloys, as long as there is enough metal left around to spread the load. Also works for fasteners that are removed very often, so is very common in avionics as well to have 300 inserts in a unit to hold the screws that are used for hermetic covers, and on aero engines as well, in the assorted aluminium castings. Just have to use the right recommended corrosion treatments when assembling them.
The differences are more in how consistently you can install them. The chinese kits sometimes cross thread due to low quality installation tools that come with them. It's really hard to mess up a timesert in comparison...
helicoils work great, they increase the diameter that engages in the parent metal, which makes them a lot stronger than the original thread, and they take advantage of the lower elasticity modulus of aluminum, spreading the load over more threads. They help prevent corrosion between aluminum and steel fasteners as well. Only problem I've had with them is backing out due to poor installation, or using too short of a screw, and pulling out the first few coils.
Seriously- thank you. This is absolutely a laboratory level test. I’m completely sold on all the metal thread inserts but HeliCoil will probably be the one I choose when needed, based on its smaller diameter and because it’s the most commonly stocked in local auto parts stores. It’s better corrosion resistance is a bonus.
yeah. ezlok and any stainless coil insert seem to be great picks for a factory grade repair. I wonder if you could use a permanent loctite on the helicoil for frequent use. do the helicoils have problems backing out?
@@robomatt1600 I have heard of people using thread locker on inserts before to prevent the inserts from coming out when the fastener is removed, so I would say yes. I was rebuilding my brother's 4.6L 2 valve mustang engine (well known engine for spitting out spark plugs). It had a spark plug thread already repaired in the past with a time sert. The time sert was not put in with a thread locker (that we could tell), & because of this the time sert actually corroded to the spark plug so bad that we could not get it off to put back in the head (needed it for the new spark plug). So he ended up having to run one bad sparkplug misfiring really badly on one cylinder until we could source a new insert. Long story short I put thread locker on the new time sert before putting it in, & I always use thread locker on all of my inserts of any kind from now on just for peace of mind. Silly reason to end up waiting to be back on the road/track or miss a car meet/show.
@@robomatt1600 I was actually really surprised that the timesheet corroded to the spark plug instead of the aluminum. That part I still don't understand.
yes.. recently I needed severAl different size inserts. I knew I had some heli coil kits around somewhere but could not even remember what sizes they were... Did a search on Amazon and several kits With the Horusdy (which works exactly as the heli coil) not only being the cheapest but with the best selection. I am all about buying 'kits' these days. I did find the old heli coil packs I had bought years ago... None of em were the right size of course... and one of em did not even have one insert used the other two had one insert each gone. I probly paid more for those three packs of one thread than I did for the entire Horusdy kit. And.. it is all organized and in a big orange plastic case. Should be easy to find in the future. Oh... this is a metric and SAE kit with about ten sizes of each. Each has it's own drill and tap... and insert tool ... Very common sizes. Can't imagine I will need anything bigger or smaller in the future. Each size comes with about ten inserts. You can also just buy the inserts and use your own drill and tap and ciobble up an insert tool from a smaller bolt that you make a slot in.
You know I used to think that I did "research" before I bought anything related to tools, power equipment, etc. etc. But you Sir take it to a whole other level! And for that, I Salute You Sir! Really appreciate and enjoy your videos! Good Luck and God Bless!
I can't thank you enough, drilling and tapping all 48 pieces then testing them, collecting data and plot them for comparision, and then producing a nice quality video. You're always the guy I go to before spending money on multiple products and running a whole bunch of trials with incorrect measurements. Im gonna try the JBweld steel epoxy since I have it in my garage, if that doesn't work then I'll try one of the inserts! Thank you once again.
As someone who has been turning a wrench (and stripping out threads) since I was a kid, and have used all of these products, this was awesome. Thank you again for your thoroughness and awesome videos!!!
I love this Channel for his realistic expiriments and the amount of thought and work that goes into the videos. He also answers the comments. Respect, keep up the work!
He is the absolute best. I feel like he could approach a tool company/monopoly and SELL this information for a TON of money. He doesn't operate like that. He helps the common man with unbiased, video proof evidence with absolutely ZERO BS and filler, or "please like and sub and comment and raid shadow legends" etc. You're the man dude! I tell all my family and my good friends about your channel. They always are somewhat uninterested because it is RU-vid but I say to give it a chance. They always are stunned how efficient and likable you are. I'll speak for him on this...remember to like the video, let him make some more money from RU-vid.
Something that I would like to see tested on this channel is sound deadening mat for automotive use. And also duplicolor has rubberized undercoating that claims to be sound insulating, I wonder if it would be comparable to different brands of mats.
That’d be an awesome test, he could suspend a sheet of steel, bolt a transducer to one end (kind of like a plate reverb design), and then put a contact mic and an audio mic near the other end, apply a four foot square patch of each brand to the middle of the sheet, and measure what frequencies it deadens and by how much.
@@ProjectFarm If you ever do such a test, be sure to test for high temps and melting goo running out of doors. The brand I went with drips out of my doors years later and destroys my door seal no matter how many times I replace it. Huge mistake on my part.
As a former motorcycle mechanic, I preferred to use the Time-Sert thread repair in my workshop. At that time the only competitor was the Heli-Coil inserts, which I had consistently not been impressed with. I did use an epoxy/metal repair material called Metal-Set to build up a sheared portion of the casting on an engine which retained the clutch cable adjuster. I wrapped a bolt in PTFE tape and after cleaning the repair area with brake cleaner, I built the Metal-Set around the bolt in situ. Once cured, I unwound the bolt, filed the repair to match the original casting and refitted the clutch cable. Despite shear load being present, that Metal-Set repair never failed. The customer couldn't afford to have the repair carried out in the conventional way, and my method met his budget and worked perfectly (and was guaranteed by me). From my experience, I regard the Time-Sert as the best of the type, I have never had one fail, and with the application of Copaslip never had one seize or corrode either! I have very successfully used Araldite (Not Araldite Rapid!) to repair deep pitting corrosion in motorcycle front fork tubes. After stripping the forks and thoroughly cleaning the pitted areas (it was extensive!) I filled in the holes with the mixed Araldite. Once set, I sanded the repairs to the chromium surface of the forks, cleaned it and rebuilt the forks with new seals, oil and fork gaiters. The owner couldn't afford to have the fork tubes re-chromed and my repair meant that the forks never again leaked and would pass the MOT Test, (I warranted the fork repair too). These repair products are an invaluable aid in the workshop and when correctly applied will give permanent, high quality repairs. Your tests are fantastic, and I have benefitted from your research and findings.
I had to do multiple thread repairs on a Honda crankcase, not much material to work with. Heli Coils with their smaller diameter worked fine. An aviation technician told me that's all they use, and all OEM assemblies come with HC.
I've never used Time-Sert. I've also never had Heli-Coil fail on me, guess if they do I have a very expensive alternative now. :-D I was impressed with the fork repair, I don't work on motorcycles. I know that some of the structural adhesives used in collision repair are very impressive. I'm kind of wondering how they'd work for thread repair now, just for giggles.
A properly installed heli-coil will ultimately outperform any other threaded insert, heli-coils are approved for use in aerospace while time-serts and others are specifically prohibited. I wonder if the FAA, in conjunction with the entire aerospace industry, got together and used their combined experience with testing and engineering to evaluate the performance of threaded inserts.
One thing to note about helicoil style is that the are stackable, so you can use almost three for an engine head bolt ! Also to note, due to the new aluminium hole being larger, threads have more meat to bite into, so almost always repair will be stronger.
I don't understand what's the point with these repair kits. You can just bore the hole bigger, make bigger thread and install a bigger bolt. Much easier than with repair kits.
finally drilled out snapped AC compressor lower mounting M8 bolt from my Fiesta's aluminum oil pan and was going to use Loctite to try to fix new bolt in the damaged thread. This video is just in time - ordered from amazon $25 kit for all kinds of metric threads, similar to Heli Coil. Project Farm, you are the best
Thread inserts are not just for thread repair, they are installed all the time from factory in aluminum castings and other similar parts. I've made a lot of aerospace parts that have heli coils installed with traceability paperwork even. Another thread repair that is done a lot in the field is to drill&tap , install a larger bolt, cut it off flush, loctite or tack weld or stake in place, then drill and tap the original size in the hole, sort of like build your own insert. If done well its a solid repair that you can do with just a tap and die set instead of having to go find the correct thread insert set. Also is great if the original hole is very damaged and so over sized so you can't just use and off the shelf inserts system.
That same idea is done in wood working with gluing in dowels to fix mistakes or fill in worn out screw holes. Any difference in strength is very minor as the wood glue is stronger than the woods used as long as you give the wood glue time to cure first.
I've done the oversized bolt trick many times in my little machine shop when i didn't have the right helicoil kit and it's always worked great and there's no waiting around for the right helicoil kit to arrive
I've been designing a light aircraft, and this has been an area of concern. The engine (85-90kg) is supposed to bolt to 4 points in an aluminium bulkhead/firewall. Which type of thread insert would you recommend, based on your experience? Please feel free to be as specific as you wish. Thank you in advance.
I have a 6.5 diesel block that was bought with starter hole problems. One hole is re drilled off center and oversized. Been thinking about having it welded to re drill. But now I think I'm going to try the oversize bolt trick and drill/tap it to OEM size and location. Thank you for the idea.
Thank you for doing this. As a mechanical engineer I have to applaud your excellent experimental design and your willingness to put all this effort into answering the question of which insert is best. I can see this video becoming everyone's go-to reference when this question pops up again from time to time. Since you asked, here's some suggestions for improvement for future videos: 1. Since you have three values for each test, work out the standard deviation (you can use the stdev() function in Microsoft Excel) and use that value for the error bars in your chart columns. As a rule of thumb, if you see the error bars overlap with those of another column in the chart, then you can say that there's probably no statistically significant difference between the two (i.e. any difference is likely due to chance, not an inherent strength increase of the thing under test) If one of the error bars is much bigger than the rest it means that test had much more variability and you might want to do more samples. The copper tests for example had huge variation between each reading, so the standard deviation (and hence error bars) on that would be huge, meaning the results should be taken with a pinch of salt. Of course that's an important result in itself - you can safely conclude that in the field, using a copper wire is a huge risk because you don't know how much strength you're going to get (as evidenced by the results being all over the place). 2. In cases where the bolt snapped, you're not actually testing the strength of the insert (obviously) so to be fair, you shouldn't report that value and rank the inserts by that value - in reality you should just write "bolt snapped", and tie all those inserts in first place in the rankings. But obviously this is a RU-vid video not a scientific paper, so we all understand that there's no need to be 100% rigorous about this.
I noticed that those bolts broke. That means next time use a stronger bolt. A broken bolt means the test for that product is incomplete because you aren't supposed to be testing bolt strength.
@@leewilkerson8185 So what if he goes with grade 8 bolts and they break? Or the inserts pull the aluminum threads out with them? We could do this forever, and eventually he’s spending a lot of money testing exotic metals to find out the best way to repair damaged aluminum threads. Best way is when possible just chase the threads with a tap and be done with it.
@@leewilkerson8185 The thing about Project Farm is that he performs experiments and reports results in an operationally representative manner. For most people, the difference in strength between the inserts is irrelevant. The question is just, given typical loads and materials, will this insert hold up better and give more consistent results than glue or nothing at all? The answer was a resounding yes. If the insert is so strong that your typical bolt will break before the insert does, that's all we need to know.
My man! I love watching these. You’re the reason I got the vacuum I did. You’re the reason I use the specific penetrating oil, I love the work you put into these. You eliminate all the guessing games and anecdotal evidence normally needed to choose a product, especially the more high dollar ones. Thank you!!!!!
Don't forget that the Helicoil, and the Time-sert and E-Z lok are all available in Stainless Steel and even mill spec stainless. They are also available in low profile (at least the Timesert) and Mil-spec.
I had studs falling out of the head of an engine. Helicoil kit I bought was solid. It became an entirely different car once that giant boost leak was eliminated, also an entire new set of issues 😂
"Mil-Spec", i's a catch phrase that sounds good but actually means nothing unless you know what the spec says. Without actual certification it is just a con like "Aircraft Quality" aluminum.
@@deconteesawyer5758 correct. In the case of the inserts it is materials, certification tracing, and certain thread standards. Just letting folks know it IS available. In a past life, using spec certified hardware was important (for some reason, the military cares about it, particularly for flight hardware). We didn’t even allow non traceable stuff in the building.
@@CharlesGallo If I want some Mil-spec hardware or aircraft parts I will contact the Taliban. They are currently better equipped with with that than two thirds of UN forces, as they were recently gifted 90 billion dollars worth. If l want a reliable insert with good quality control, material specifications, thread form, and strength I will just get a commercial insert from a good brand name American company like Heli-Coil and rest assured that it's tensile strength exceeds my needs. They are Mil-spec suppliers and have a ton of Mil-specs listed on their website, so there is a good chance the product is already Mil-spec without my thinking about it or asking for that. And in addition even if for some reason the product I selected was not Mil-spec they have the advantage of being produced in a quality conscious environment much like what you described working at, and meet or exceed numerous other quality, material, and process certifications. We can up that with NASA certified inserts, somehow important to space flight folks. I just want to make folks aware you CAN get those too.
Just watched both your video and the one from Torque Test Channel and fully appreciate both data sets. The fact that you both posted at the same time and had similar results from different approaches and products was pretty fantastic to be honest. Keep up the amazing work!
The thread repair I'm most proud of was in the nightmare scenario of a stainless steel reverse thread driving a nylon shaft that direct drove an auger that dispensed powdered chocolate and sugar in a coffee machine. I found just the right thickness of steel wire (0.8mm if memory serves) and wound it around the steel thread to form it then tightened it a little and screwed it into the nylon part much like the thread repair kits shown here, it worked and lasted for the remaining years until that coffee machine was replaced.
My favorite: A family friend (my wife's former student) was in college and her Honda Civic had a bolt strip (on the alternator bracket or tensioner) and each shop told her it was not repairable. Her parents were trying to convince her to purchase a new car which she could not afford. We were trying to convince her to repair the car and minimize debt. I ended up buying a time-sert kit and new bolt from the dealer and was able to repair it for her. She has since graduated and is an elementary school teacher, wife and mother. Her husband drives the little Civic as his commuter car and I can't help but smile every time I see that car or the time-sert kit in my tool box.
I take my hat off to you. If anyone suggests your tests are not thorough or scientific then they’re on a different planet. You deserve a medal for this test. Very interesting results.
Years ago when you first started your channel, I left a comment "Really good guy, I wouldn't let him barrow my lawn mower " and you responded in a joyfully way. In the years Since then you have saved me easily enough money to buy a really nice lawnmower. So I will now Comment "Great guy, no BS and will save you Time and Money. If he ever needs a lawnmower I would just give it to him" Cheers!
Your dedication to bringing this valuable information is impressive. Thank you for your reviews. You have saved me and many others a lot of time, hassle and money.
I was especially interested in this one. It was very insightful. An interesting thing about the inserts is that they are very often used in parts from the very beginning, especially in softer materials because the insert allows for better holding power with that size bolt than you'd get from that bolt being threaded directly into the softer material. I think your average person will have never heard of helicoils or other similar inserts. Boy are they useful at home in the garage. Thanks for the video!
well for aluminum bronze inserts are harder and you have also corrosion resistance. I was thinking he was going to test it on mild steel with 10,9 bolts, with that setup its only interesting with the chemical repair
Exactly. My edelbrock victor jr aluminum heads, for a small block Chevy have helicoils installed from the factory. (rocker stud holes, and exhaust Manifold holes)
In doing the timing belt project on my VW diesel, I discovered a prior mechanic had stripped one of three belt tensioner bolts. It was the one common to the aluminum coolant jacket. After some research, I chose TimeSert, called them explaining the situation. They didn't have one with such a shallow thread depth, but suggested I could customize it. I told him, no problem, and please overnight it. They were very helpful. That was about 8 yrs ago. Great product!
This was one of my favorite tests. I would love to see this done again with stronger bolts, and maybe also ones made for sparkplugs. The added heat would be an interesting factor.
Yes! The one time I had to do this was for a spark plug. I used a metal insert, but to lock it, you tapped the top with a provided punch to stretch the top and lock it into place. This was an extremely interesting vid for me!
3:14 To figure out the size of the tap drill just subtract the tread pitch from the nominal bolt size. For example M6 × 1 needs 5mm tap drill. M8 × 1.25 needs 6.75 tap drill (round to 6.8)
Excellent subject and video! Years ago when Helicoil was pretty much the only option, a lot of airframes and engines were built using the Helicoils. I built 2 stroke racing engines back in the 70s adapting pieces to the blocks, jugs and heads and used helicoils for doing so. Pretty much can guarantee that those if they haven’t been recycled are still holding. I have a few 1950s-1960s Ford Y Block engines sitting in the hangar on the family farm and because of two of the head bolts on them being close to the same length but not quite, a lot of those engines when rebuilt would have the wrong bolts used on the heads and they would strip out the threads in the blocks. I like the Time Sert and intend to purchase the kit for those size threads. I like the chamfer of those. Thank You for publishing your videos!
I use heli coils at work nearly on a daily basis. it's amazing how many are in aircraft parts. seeing how well they hold up makes me not feel so bad when I have to repair a cnc machine with it now.
@@jpikl1284 Still will hold out, as the larger diameter thread into the parent metal resists the pull, plus it is spread out over a larger area of the very hard wire.12.9 grade yes it will still rip out, but at a much higher load, and you can always use a much longer insert or multiple inserts, as I have done on deep holes.
This is so appreciated. I stipped out a motor mount bolt hole on my S2000’s aluminum engine block 💀 and now I know which thread insert to use. Thank you thank you!!!❤️
would be very interesting to see this done with grade 8 bolts. appears that all of the inserts held equally with a hardened bolt should be able to see the inserts pull out of the aluminum and in theory the bigger inserts in diam should hold better
Look for a channel called "torque test channel" and watch their thread repair video it has batter information they didn't use aluminum so they had some thread repairs actually fail
@@juststuff4381 yea I saw that after I commented. But would still be interesting to see it. Most of the time when im doing heli coils it's in alum housings on engines. Very common for some jack azz go get over zealous tightening bolts with a impact and pull threads
The diameter is certainly important, but a second factor is that the pricier ones have one-piece designs so they won't 'uncoil' out of the hole if things get ugly. Far better repair for something that is going to be removed at least occasionally, but more money.
Im a machinist and at my work we used to use the helicoil ones, but switched to the ez lock ones. They hold up much better for bolts that are removed repeatedly. Most of our fixtures are aluminum and threads don't last long with repeated use.
For my Jeep transmission Bolt which requires 10 to 12 inch pounds copper will work for me . Project Farm is my absolute favorite channel for Improvement projects you are absolutely the man💯💪 I forgot to add because of project Farm a shop wanted to charge me $500 for a project and thanks to this man it cost me $38 and twenty-five minutes of my time.❤
Just when I need to buy something, Todd comes good again with a totally unbiased, impartial test. Thank you so much for saving me time and money, and also thanks for saving me from making a worse job of an important restoration project. 👍
That is extremely interesting that ez lock gave so much more support to the bolt that it broke with almost 300 more in lb. You would think a sheared bolt was a sheared bolt but this test proves something. I'm guessing it's that flange so the bolt has to break right at the head which would explain the 200 inlb difference between the others that is wild!
TBF it shows the tests aren't so consistent. It would be much better if he used a longer flange and a steel washer because the aluminium got all mangled up and caused friction...
If it’s statistically different it has to do with a variable thread pitch. On a straight threaded hole and bolt only 1.5 wraps of thread hold the entire load. If the insert stretches it could possibly spread the load further. The head or the top of the threads on a partially threaded bolt are where stress concentrates to cause failure. The fact that the grade 5 bolt broke says they will meet your needs.
I'm not sure how to interpret that. I think ultimately they should have been tested with some sort of washer and bearing surface to reduce the influence of the insert 'biting' the bottom of the bolt head - almost certainly the reason for the increased torque on the EZ lock. It may have tested be higher, but I don't think it's a benefit either way in a real world scenario.
Great stuff! I use E-Z LOK almost exclusively. I always thought Time-Sert were the best, but after seeing this, I'll stay with E-Z LOK. Time-Sert forces you to use their taps and those taps are really rare/hard to find. E-Z LOK is a better deal for cost. Decades ago I started with Heli Coil, but found they gall if you use the threads repeatedly. And...they are very hard to remove and do again as they tend to unravel/break. E-Z LOK has a full range of inserts and even for wood products. They have thin-wall metal inserts too which really come in handy sometimes.
It's funny you bring up wood products, that's how I started using E-Z Lok in the first place after some generic wood inserts started pulling away after a few years on a table I built.
Of the options tested I've only ever used Heli Coil inserts with 100% success so far. Nice to see them come out on top here. I'd never been tempted to use one of the liquid fixes tested here and now I'm even less tempted to try them. Thank you Project Farm for a job well done.
I like Helicoil if the bolt isn't intended to come out repeatedly. I've had the inserts come out. I prefer time-serts for things that get disassembled periodically.
As a Machinest/Toolmaker I really appreciate the quality of the test and the video! We always use Steel Thread Inserts on all aluminum components.. Great video Buddy!
I've always used "Heli-Coil" inserts, from way back in 1964 to repair a blown out spark plug to the present. I have, by now, a fairly complete set of both SAE and metric kits. The spark plug kit cost me ~$50 to fix a car I just bought for $750. One advantage of the "Heli-Coil" is multiple insert lengths.
I use time serts after I owned a North Star engine that stripped out almost all the head studs. They multiple lengths also. Not sure about the other brands though. I always red locktite my solid inserts also.
I used helicoil a while back on an aluminum engine, and suspected the connection was stronger with it than without. This test supports that idea! Also, it's very cool to see tests for torque AND straight pull out.
Years ago my Brother and I did a similar test. He swore by TimeSerts and I said they were no better than HeliCoil. It took a lot of broken bolts and a fair amount of cussing, but we came away with the same results you did. No one steel thread repair was any better than another. Some were cheaper, some easier to install and some kits we're more complete than others, but once installed they were all equal.
Every time I go down a path of trying to figure out what's the best solution, these guys have a video on it and helps me a ton. Thanks to you guys for all the work you do and how thorough you are in your testing.
If you do a part 2 to this, try some Keenserts. They are by far the strongest and most permanent way to fix a threaded hole. As a machinist I've had to use them on applications that are heavy duty and can not have the insert vibrate out (other inserts types like helicoils can vibrate out).
One other way threads can be stripped out is to use an incorrect metal, or substandard quality metal in a given application. For example, Ford Triton V8 engines (as in the Crown Victoria and others) used aluminum cylinder heads, and over tightened the plugs at the factory. The constant stress on the threads made Triton engines notorious for blowing out spark plugs due to stripped threads. I wish I'd had your video years back when I had to fix my ex sister-in-law's Crown Vic.
Another reason for this on the Triton is that the wall around the combustion chamber is thin, so the length of threads is too short for aluminum. It's more like what you should have for an iron head.
Blew 2 spark plugs on my 2003 Cobra (4.6 liter engine). Used the time-sert one time and heli-coli the other. Both held up. Those engines were notorious for blowing plugs.
01 f150 with the older 5.4 blew out the front 3 on the passenger side mechanic put the helicoils in no more problems (kinda waiting on #4) but she has over 350 thousand on her! a great products made her run a lot longer!!!
Another great evaluation so I just bought a Helicoil kit to fix a stripped out bus bar in an electric panel. I felt this was the best choice since the repair needs to provide a zero resistance connection between the breaker and the bus bar, and the Helicoil/HHIP solution provides a metal to metal fit. I did think about just tapping out to the next size up but figured this might cause problems for future adds/changes in the panel. Thanks for all you do!
I always use Heli Coil kit, I have never had one fail after 15 years of building Motorcycle motors. After all, it is standard practice in building airplane engines.
@@ProjectFarm My cheapest ones were actually US standard sizes, they had not moved off the shelves for 40 years, since the country went metric, so were finally on sale, for only double of the price in 1970, so I picked all of them they had up. Only 3 sets, but covered all the US standard sizes I used on US built machinery, 1/4, 5/8 and 7/16 standard thread. Also got the 7/16 die nut, so I could make the shear pins that used that thread, instead of ordering them, at a ruinous price. 1metre of 12mm stainless steel hex stock made a large number of those shear pins for use. Machining the pins, plus the tooling, came to the cost of only 1 pin, and I got over 20 of them, with bar left over.
One thing to keep in mind with thread inserts is galvanic corrosion. For example, carbon steel inserts in a brass piece may experience extremely rapid galvanic corrosion if exposed to water, especially salt water. Make sure to check that both materials are relatively near each other on a galvanic activity chart.
Indeed one of the concerns. Like in some applications with water pump installations, standard steel bolts are used. Eventually pieces weld together. Timesert makes inserts in stainless steel. Probably a better choice for aluminum.
The thing to remember is that Helicoil and HHIP are spiral wound where Time-Sert and E-Z Lock are soild. The spiral wound inserts can leak fluids due to the minute spiral gap, especially with thinner fluids under pressure. For this I recommend the solid inserts. In fact, I think you can get Time-Serts with a closed bottom for this very reason
For something like a drain bolt, you just need a flush surface and a large enough crush washer. Or a Dowty seal, which is a steel washer with a O-ring inside.
EZ Lock is also not regarded as gas tight unlike Time Sert which is regarded as gas tight thanks to the insert being expanded when it is fitted. The biggest disadvantage of EZ Lock, Helicoil and HHIP is that they tend to unseat themselves in applications which require frequent disassembly (maintenance covers, spark plugs or sump drain plugs). EZ Lock is worst in this regard especially in assemblies which experience considerable heat cycling and can be slightly improved upon if it is fitted using thread locking compound which both secures the insert and gas tightens the thread. A further disadvantage of EZ Lock is its size. I work on motorcycles and in many cases there is not enough space to fit an EZ Lock. From 25 years of experience with hundreds of Time Sert repairs I'd say the system is absolutely worth the money and the repair will not fail as long as it's executed correctly..
@@ProjectFarm I had to use helicoil for a timing belt idler on my subaru engine block and I've had zero issues. I can safely recommend it for moderate load applications
Had a cousin who was building an aluminum frame section for a custom trailer to tow behind his ATV. Most joints had though-bolts with proper nuts on the other side, but some parts had clearance issues and he opted to tap the aluminum. Referencing an old custom motorcycle show I'd seen, I mentioned that pre-installing inserts for the tapped holes would be more reliable. He argued that it didn't make sense, and adding inserts would just introduce another potential point of failure. Not wanting to be THAT guy, I conceded. Saw him a year or so later at a cook-out where he brought supplies with the ATV and trailer. Since I never saw the finished trailer, I wanted to check it out. He showed me the dump function, and I noticed the inserts clearly visible on the back side of the aluminum frame. The "I told you so" I kept to myself. It was a really cool little trailer that worked for carrying mulch or a few bags of sand or concrete... or a couple of cases of beer and hotdogs. Good to see some actual test proof instead of relying on anecdotal advice from a 20 year old show I saw once.
Im probably wrong but I think the inserts are usually stronger when they're in aluminum, because now the bolt is pulling on 2 sets of threads which are now in double shear, along with the steel insert being stronger than the aluminum. Makes sense but it's hard to wrap your head around because it's still just a bolt in the same material, kinda counter intuitive
@@MegaDysart I was under the impression the inserts are stronger as the thread in the aluminum is bigger. Like up to 3mm bigger. This means that the threads they sit on have a higher circumfrence and by that also higher surface area and more material to sit on.
@@MegaDysart I thought it didn't make sense because the thread of inserts are only slightly bigger. But then i saw this part of the video 10:45 where he shows that when the bolt is not turned then the aluminium thread itself is strong enough to even break the steel bolt instead of stripping thread. So i think maybe it's because when you turn the bolt and there is no more way to go, then the sharp edges of the steel bolt will start cutting the softer aluminium?
One really important advantage about the timecert is that it does not have a tab that needs to be punched off. It's also the least messy method if you are concerned about shards of metal falling down into the hole you are working on. Just pack some grease on the bits to capture metal shards. I used timecerts to repair the spark plug threads on my BMW's head. It was the only method where I could keep a glob of grease on the tools, and capture 99% of all metal shards, and do all the drilling by hand. The resulting hole is also much larger than what you drill with a helicoil, so it was easier to get a shop vac extension into the hole to suck up any stray metal shards.
Same here. I have used the time-sert set for several spark plug holes in aluminum heads over the years. It can be done without removing the head, and without any extra tools. I have done several small outboard motors this way. Time-serts are really great.
@@tdc7 Tapping isn't the messy part, since taps hold grease really well to trap shards. You aren't removing very much material when tapping anyway. It's the hole boring part that is messiest. The Timecert that is large enough for a spark plug comes with a hollow boring tool, which holds grease extremely well. That boring tool is also really easy to use with hand strength. A typical spiral drill bit you use for helicoils is really hard to turn by hand. You want to drill by hand, since that keeps shards from flying and keeps the grease from being flung from the bit. The Timesert boring tool also aligned itself perfectly with the stripped hole. You would insert a pin into the stripped hole, then the boring tool would slide onto the pin to keep it perfectly aligned. This further helped with keeping shards out of the engine.
You can stop shards/swarf ofalling into the engine if you turn the engine to a position where the exhaust valve or port is open on the cylinder you are working on, and connect an air blower to the exhaust pipe.
I've used the Time-Sert kit to repair 2 stripped out spark plugs on an aluminum cylinder head. It is expensive - but I found it works fantastic. The repairs lasted at least 200,000 miles - which included several spark plug changes along the way! I was able to make the repairs without taking the head off the engine. We loaded the tap up with grease to catch any chips, and cleaned it off every few turns. I recall using some sealant on the insert, and had no problems with compression leaks.
when i need to repair a stripped spark plug hole, i set up a shop vacuum to blow air through the hose and then duct tape it to the tailpipe. with the vacuum running, i bar the engine over with a wrench until i feel air blowing out of the bad spark plug hole, then i drill and tap the new threads letting the air blow the chips out of the hole so they can't possibly go into the cylinder.
I’m also curious about backing out a well-tightened bolt on these. I mean, tightening it until failure is pulling the thread toward the bolt, so at some level is self-reinforcing the strength, and isn’t testing the holding/gripping power of the inserts. Maybe a strongly tightened bolt, then an effort to remove it. Do the threads come out with it? And do other things affect it, like heating and cooling cycles (like often would happen in engine repair)? Being picky. Absolutely love your channel, and all the effort you go to, to make these tests as objective and useful as possible. You do us all a great service.
At my work we have an old de-watering auger with a cast iron cover. This cover get removed everyday for cleaning. Over the years the threaded inserts had stripped so I ordered some heli coils. As long as you have the proper size and thread count and you dont overtorque them too much the coils shouldnt creep out. These were 316 SS bolts into a cast auger cover.
As an engineer at a cheapskate factory, I use a lot of these spring style thread repair kits in equipment that gets hot or wet, bolts that get tightened down with far too much torque and bolts that come in and out dozens of times each day, the inserts just will not back out no matter how hard you try but can work their way further in. In general the thread repair isn't the bit that fails, it's usually (and in aluminium always) the base metal that fails first, they don't really rust or get bound up. Their only weakness is if you ram in a damaged or cross threaded bolt or don't realise it's a thread repair and try to run a tap down it. Then you get to suffer.
For heat concerns - we use heli coils in the hot section of turbine engines for threaded hole repairs. If you're concerned about backing out the coil, stake or peen the top and the thing is never coming out... but you've now made that a one time repair. Soft aluminum/magnesium casting for propeller gearboxes, we use threadlocker to prevent backing out.
all inserts fared equally well I would say, doing better than the original test piece under torque load. I guess turning the bolt into a higher diameter bolt in some way could be the secret here. For the bolt breaking different geometries may be relevant here, as with the bolt breaking, this more tested the bolts strenght than the insert, geometry and size or smoothness of the insert may well cause the varyations here. Which however does not render this test irrelevant, as it shows it is now the bolt we have to worry about while the insert is fine. But the JB weld and the Loctite thread repair did also better than I had expected. I guess for certain applications with lighter torque and push/pull loads and hard to reach bolt holes, they may indeed be an option. Even the thread locker did more than I expected, and to be fair, this test was way out of the products "comfort zone". For the second test, I think we can conclude the the bolts tensile strength was reached at around 1000 psi in this setup. Not sure what that would calculate as in foot pound or Nm. I wonder what those results would look like with a higher tensile strength bolt. I guess at some point the insert would simply be pulled out of the aluminium at varying forces. the higher diameter inserts may be at an advantage here.
Thank you for ALL the testing I went with the Heli Coil kit on my brembo calipers. So far the repairs have lasted very well with regular brake bleeding and nipple replacement every 12 months
YAY! You're doing a 3-sample test on each subject. That's infinitely better than just 1 sample as you do in most other videos. Did you notice the variability among some of the samples in the same subject? NOW you're doing meaningful testing. 5 samples is even better... throw out the lowest & highest, average the middle 3.
I used that loctite thread repair kit to hold a spark plug into an engine head. It actually held it pretty well even though I was to scared to try and remove the plug after the repair
The last time I replaced spark plugs on a car I'd bought new, was either in the '90s, or maybe the '80s. Most cars come with platinum or rhodium-tip plugs now, which pretty much last forever if you don't have an engine problem fouling them. For instance, I bought a 2003 Silhouette minivan new, and never changed the plugs before I scrapped it at 190K miles. It was still averaging 26mpg, exactly the same as when new. (I run "max load at max psi" tire pressures on the tire sidewall, and don't drive like a maniac, for anyone disbelieving the mpg in a loaded 7-passenger 2003 minivan with 3.4 liter V6)
@@EfficientRVer i use iridium plugs in a turbcharged mitsubishi and they do slowly degrade over time. Though i expect my car is much tougher on plugs than a stock power level minivan that likely makes less than half the power mine makes per cylinder.
The time sert is actually what use to be called Keensert. Hope my memory is still good here. These are the best repairs period. They can be bought in corrosion resistance grades. But like anything it all depends on a few usage factors. Nice work as usual PF. Keep on making great recordings fella.
They are close. The Keenserts have the locking wedges on the outside threads of the insert that lock the repair in place. They use a tool which fits over the wedges that drives the wedges through the new threads locking the insert in place so that it will not back out.
Great video but I do have a note about the analysis for the heli coil, time sert, e-z lok, and hhip: Since they all break due to the bolt breaking under load, you can't rank them based on the force it took to achieve a failure. You certainly can rank them qualitatively based off of ease of use or price, but you can't say that any of them performs better quantitatively based off of load at failure since we are concerned about the failure of the repair method, not of the bolt. Again, I love your videos so keep up the great work! If you want to talk more about this analysis or any other analysis process let me know and I can try to help as best as I can
My thought, exactly. Why even show the force at which it broke? These bolts should be strong enough to exceed the predicted force need to destroy the samples. Another test channel makes the same mistake all the time. It makes no sense. You're the only one I see that picked that up. Excellent thinking.
@@alext8828 Yea, I'm an industrial engineer so I do a lot of statistical analysis on processes and try to obtain meaningful data. It can be tough to get sometimes and especially tough to look at your own testing process to see if you get meaningful data
The one big advantage the Timesert has is that it flares at the bottom and won't back out. I quit repairing stripped spark plug holes with Heli-coils and went to Timeserts for this reason. Every time I would change plugs, I'd have to use another heli-coil or remove it from the old spark plug and screw it onto the new one.
If a heli coil is set properly (at least 1/2 turn below surface) it won't back out... I've done dozens working in bike shops, and always had better results with heli coils than time-serts.
@@ProjectFarm I particularly like how you included a little extra education in the beginning for less experienced viewers, without taking too much time or boring experienced viewers.
Great video! I use a ton of the EZ lok threaded inserts at my work, couple hundred a month or so. They’re super durable but the threadlocker that comes on them can be pretty messy.
Really great testing video! I was very surprised to see how much more torque the threaded inserts can handle compared to flat aluminum stock alone that's threaded.
I think it really depends on the application. I've used heli coils for non critical applications but tend to use time-sert on more critical applications such as brake calipers. Or head bolts. Also, if the bolt is going to be in and out a lot I like time-serts for that application. To note, Time-Sert also has another product call "Big-Sert" which are used to repair failed thread repairs. So if you drill out for a heli coil and the heli coil fails, you still have the option for repair. Again, great video my friend.
This video came up after I had been looking for M14 x 1.5 thread chasers, sort of related, but once I started watching your video, I couldn't stop. Excellent, fast-paced presentation and I sure learned a lot. Thanks!
These are interesting results, I wasn't surprised that insert repair kits were better. My company uses Helicoil and I have never seen a part come back to be re-repaired for thread damage. You do amazing work testing throughly and in the most controlled way I have seen on a RU-vid channel. Keep up the good work
I used the reviewed time-sert kit on my snowmobile oil drain hole last winter and couldn't be happier with the result. For repairing an installed part where you don't want to be punching tabs into the oil pan, and also when you need a low profile insert, I would recommend the time sert. It's worth the money. Also one tip, to catch chips when drilling and tapping, use liberal grease on the tool, the chips will stick to the grease.
Used a timesert kit on my 2005 crown Vic after it blew a spark plug out, second time it ejected a spark plug in the 4 years I owned it Was pretty easy to use, if a little expensive I used lots of grease on the bit and compressed air Sold the car to a buddy who flipped it to a neighbor, still running around somewhere
Theres a brand of grease called Assembly Goo (should be blue colored) that is designed to melt and dissipate in high heat, meaning its safe to use in more sensitive internal components as well. I use that on both the bit and surrounding areas to catch chips in more sensitive environments
I used the Time Sert on a very tricky repair of a threaded body tube on a Honda rear suspension trailing arm. The threads are inside a threaded "tube" that is sandwiched (captured) inside of an internal frame rail. Every time that vehicle comes in for service, I always take a torque wrench and set it 5lbs below factory value to insure it is maintaining the torque value. We are about 2 years and nearly 10k miles and the repair is rock solid.
Great video as always. Thank you for testing this for us. Just a note on my personal preference. I have actual thread checkers. I prefer them to calipers and that thread gauge. It helps when you aren’t sure if it’s standard or metric. Also if you talk to the helicoil manufacturer they recommend using flat nose/needle nose pliers to break off the tab. They have an unbelievably wide array of products even within the same thread size although finding them may be difficult if you are not an industrial customer.
@@consaka1 Basically a specially machined bolt and nut, with 2 ends, where one end is the minimum size for that particular thread diameter and pitch, used to check the thread is not oversize, and is the go size, in that it must fit without binding, and must be firm with no wobble. The other side is cut to the maximum diameter, at least just past the first few turns, and should engage a turn or so, so that you are sure the thread is not oversize as it stops going in. For the nuts the first is the maximum diameter, and all bolts should fit with no slop, and the other side is the minimum, and it should not go onto the bolt after the first turn or so. Unfortunately precision parts, and you need one of each double ended tool, per fastener pitch and diameter, so these are not common, normally used only for very close tolerance work where you are running the fasteners at a very close tolerance and at a very high loading. you normally see them in aviation maintenance, where they are used when rebuilding airframe and engines, to determine whether a fastener, which is normally an expensive part, as the cheap (under $5 each) fasteners are simply regarded as a part you throw away each time. These are for the more expensive ones, where you will use the gauge to check the fastener, and the hole, are still within tolerance, so as to allow them to be reused. $500 gauge, used to check a $1000 plus bolt, and the gauge itself has to be calibrated and certified annually, or more often, depending on use. Half of an aircraft repair facility toolbox is special measuring tools, so they use a Snap On toolbox, as that is often the cheapest single part in that tool box. Spanners have serial numbers in a lot of cases.
No kidding. We had a case at work where an engineer reverse engineered a design and came up with using #4-40 screws on a new design that used some of the old parts. Turns out the original design was from Sony in Japan and the screws were M3x.5. Then when we tried to assemble them, the countersunk screw heads would all stick out and the unit wouldn't slide into the rack. It took forever to figure out what was going on, until I was talking over the problem with one of our machinists, and then the lightbulb went on in my head. Thank god that they hadn't used #4-48 screws, which are almost exactly M3X.5 size.
Can the testing be done with grade 8 hardware or even automotive grade studs?? I'm curious to see the results of the Metal thread repair kits with stronger bolts.
My old folding sawhorses just broke. I went to buy new ones and they make claims that don’t seem realistic. I’d love to see a comparison for which ones hold the most weight, resist rust, and especially resist swaying (that’s what killed mine). I look to your channel as the authority on these things now.
@@sbukosky build one yourself. Will have everything you need (cuz you built it) and will fit perfectly (cuz you built it) and will make you feel good (cuz you built it)
The best sawhorse is the one you build yourself. Only you know what the sawhorse needs to sustain to be a valuable tool to you. I've never bought a sawhorse that could handle the pressure I put on too it with my foot to keep it stable. So I ended up reinforcing them myself
Cool to see your test results. They turned out how I expected based on my experience over the years. On some builds I will use Heli-Coil inserts to reinforce the assembly. I like how you added some fun commentary when the results were getting a bit repetitive. Thanks for another fun and useful video.
This man is by far one of the most resourceful people on RU-vid. The Gandolf of DIY! If we had one of him in every local DIY store like the old days, the world would be a better place. 👍
The attention to detail, the fortitude to complete the laborious tasks for your videos sets the bar high, a unique channel a great host and old fashioned honest programming, the pleasure is all on the side of the screen . Well done sir, well done !
I’ve always been a huge fan of EZ Lok. I’ve tried all the “at home/diy” thread repair methods and none have them have worked for me so I gave in and bought a thread repair kit and the first one I bought is now the only one I use and trust.
The worst part about thread inserts is sometimes they unwind after threading the bolt in and out multiple times. I usually red loctite my helicoils to help prevent it. Time serts are my favorite just cost prohibitive to have an array of sizes on hand.
Excellent testing! I didn’t see this one coming, but love the results of using real inserts. JB Weld has it’s uses, but it certainly doesn’t beat real metal as a fix.
..yes, exactly!..that has always been my peeve with JB Weld...it's name!..It IS NOT a weld!!..it does have it's uses, and I do use it, but not as a "weld", or any application that requires sheer strength...
Thanks for another great test and a huge amount of work to set it up. I'm confused by the results, however. Once you reach the point of breaking the test bolts, it becomes a test of bolt strength, rather than female thread strength (other than up to the breaking strength of the bolt). So the fact that the EZ-Lock tested so much higher than the other thread insert products just means that the bolts were stronger, although it seems an odd coincidence that all the bolts used with that product were so much stronger than all the bolts used for the other thread insert products.
No, it was also checked that the threads were still fine and shaped, not ruined, after breaking the bolt. For the EZ-lock difference I points to the size of the coil: others were smaller, EZ was the largest (nearly 12mms); this leads to a wider surface exposed between lock&metal (hence applicable force).
@@Quartolone This has nothing to do with the bolt breaking strength though. That would only explain "if" the ez lock insert had a higher pull out force then others. Given the replication on the result 3 times, there must be some explanation, but that isn't it. My guess would be it has to do with the consistency of the threads of the ezlock insert dispersing the force more evenly over the length of the bolt. Even the time sert failed lower as due to its expanding nature during install likely creates an area of slightly distorted threads which then concentrates the load in the bolt. Hence it breaks sooner. The loose coil style inserts are obviously (and from experience) are much more subject to the install technique and quality vs the solid wall inserts, again resulting in load concentration areas on the bolt. Also, everyone notes the ezlock size as a disadvantage, this all depends on the installation; some times that size (and why you can get extra thick ones) allows you to fix a completely shagged up thread back to a desired size. Ie. So it is consistent with the rest of a "set" of threads/holes.
finally. i waited years for this video. thank you. btw. you should start an internship to get free labor and have someone help you around the workshop when testing. i will volunteer to be your first intern.
Great video. The thread repair inserts being stronger than the original aluminum threads isn’t terribly surprising. Installing thread inserts into new aluminum on vehicle productions lines isn’t unheard of for the same reason: the minor diameter of the fastener increased. In other words, the hole got bigger; therefore, the threads contacting the aluminum had more area of engagement, and thus could handle more pressure/force. Using thread inserts makes the assembly stronger in most cases.
As always, great work on the testing and video. Just a few things I'd like to say. 1) Assembly of DRY steel bolts into threaded aluminum holes will quickly strip the thread in aluminum due to friction. Especially when parts must be disassembled frequently. 2) Determine the drill size for metric fasteners WITHOUT a chart. Simply subtract the pitch from the diameter, i.e. M8 x 1.25 fastener requires 8 - 1.25 = 6.75 mm drill (further divide by 25.4 for decimal drill size). 3) Too bad Keen-serts weren't considered. My customers have begun asking for these type inserts when I repair their parts. Even when the original drawings call for EZ-lok, they want Keen-sert instead.
Quite a comprehensive test indeed. I've been using Time-Sert or Heli-Coil (or an equivalent) for almost 40 years and they both have their benefits depending on the circumstances of the job in hand. Though the Time-Sert is usually the preferred option in most cases. Keep up the good work old chap.
