Metal Lathe Tutorial 15: Parting 

This women dominates what is typically thought of a MALE profession. It is clear to me, she does NOT have to go so slow in her demonstration, but I am thankful she does. This lady is AWESOME.

I’m 66years old and now retired but not a day goes by were I don’t learn something new. I don’t watch TV RU-vid is my only source of entertainment and education. A great deal can be gained by watching people like yourself who take time out to make these videos. Thanks very much for sharing your knowledge. 👍

Your parting demo was as smooth as it could be. You part with the best of them. It is scary but as long as you do EVERYTHING as you stated in your tutorial it’ll go just fine. I’ve made chatter, I’ve shattered blades, I’ve bound up my lathe and it’s all scary but as long as you take your time and do it right it can be very satisfying. Especially when you get it right and it’s new to you. It’s a definite moment of marching pride. Machining is all about pride for me. I am a big time perfectionist and just knowing the precision and all that is there even when it doesn’t need to be make me a happy camper.

Perfect English and speaking at a comfortable speed, I don't need to see the video twice to understand what's going on because your presentation is perfect! I think you're the best so far! And very good safety advices throughout. Thanks and Subscribed!

"Surefire way to end your day by picking a hacksaw blade out of your spleen"... LOL You do such a great job of stressing safety with a slight touch of humour so people will remember the lesson. Your machining videos are fantastic - most clear, easy to understand I have ever found. Great for small-machine hobbyists (like me).

Thanks for all your work and videos. I was just sharpening my parting cutter. Thanks again..

This is hands down THE BEST video on parting on the internet, bar none! If it still weren't so damn scary I'd love parting now! Thank you, Quinn!

This is my new favorite machining channel - Clickspring stopped explaining what he's doing years ago (and hasn't posted any videos in months) and while TOT still has a place in my heart he doesn't pack nearly the amount of information in that you do. Great production values, great writing, sound quality is good too.

I learned parting using rocker toolposts. And HSS tools of course. Just three more dimensions of difficulty (dementia of difficulty). That was in the 1980’s. Parting tools and tool holders have all improved to the point where parting is predictable nowadays. That’s all I have to add. Bondihacks video is nothing less than the best instruction for parting with HSS tooling. At the shop we have moved on to carbide insert tooling and we have never looked back. Great vid Blondihacks. I am impressed how some ‘hobby’ people know their subject from one end to the other, just out of the love of doing.

Parting on the lathe, it's like a horror movie. Even after all these years, when I have to cut a piece, it's always creepy. Full anxiety. But that anxiety helps not to make mistakes. Greetings, from Buenos Aires, Argentina.

One thing....I always set the blade height at or just a few thou under center....never above. I've found the initiating of any death chatter results in a shattered blade far more likely with the blade above center, even just a little. Below means the blade bounce doesn't wedge the blade deeper into the stock on the swing out of the diameter. This provides more warning to back out of the cut before the blade breaks.

No more sweet sorrow. After following your directions I was able to part using the parting tool for the first time. Slower the speed, the better. Thank you!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Something as simple as your advice with the safety button at the beginning of this video. Advising to hit the button a few times just to get used to it. I bet very few people ever would do that, but they should. Excellent the safety advice.

Thanks for this entire tutorial series. I'm considering moving beyond my woodworking tools to a dedicated lathe and mill. The level of detail, logical structure and personable style to your videos is a model for everyone to emulate.

After watching dozens of your videos, I just had to look up the history of the expression “Bob’s your uncle.” Interesting history but have to say “Fanny’s your aunt.” is just too funny. Hands down, you have one of the best machining channels on RU-vid. I have learned so much over the few months on how to appropriately us my Little Machine Shop lathe and mill. Thanks for you time and effort, it shows brilliantly through your videos and content.

Love this lady - managed to part off steel bar after many failures over the years. Not to mention the great tips in Quinn's other topic videos.

Thanks Quinn. I really like the way you teach. I have been around toolrooms for almost 40 years and never thot of shimming the sides of the blade in the holder. It only makes sense. I repost your videos sometimes to Home Hobby Machine Shop and Tools. I consider you one of the better teachers for the home hobbyist. Thanks again.

There are many machinist videos which are very interesting on RU-vid; but you are definitely the best Instructor of Machining.

Hey I just came across this video last night and I was out into the shed today. Did my first successful parting operation in 30 years! Ok I did take 25 years off. My old lathe doesn’t have a lot of positives going for it in the parting department. The golden nugget for me was that the parting tool holder is machined square vertically and the blade I have is tapered. I always thought the holders were made to deal with a tapered blade. Some quick measurements and a pice of paper folded twice (.020”) and I’m making nuts and washers Ok I also slowed it down to my slowest speed without using the back gear. I’ve been cutting stuff off with a hack saw for the last 5 years. I still need to work on the free play on the slides but hey what a leap forwards. Thank Ms Hacks :)

Parting really can be such sweet sorrow,seems like the more you do the more careful you get I guess you remember all the ways it can crah on you. As always good content thanks .

I used to suck at parting (still not great) so I would use the parting tool to start the cut, go as far as I dared, and then finish with the hacksaw. This created a nice, accurate shoulder for gauging the squareness of the saw cut. Quinn is the best teacher out there!

Thank you, thank you, thank you Quinn. I have been battling and failing at parting off on my mini lathe ever since I inherited it, to the point that I had simply given up. I had searched the interweb and RU-vid and tried many solutions to no avail. One day I discovered a channel called Blondihacks (insert anjelic chorus here) and my world changed forever. While cruising your back catalogue and soaking up the knowledge generously provided, I discovered your advice to shim my hss parting blade. Voila! This turned out to be the holy grail I had been searching for. I used my tweaked tool today and it worked perfectly, just like the big boys do it. 😁 You even inspired me to post my first ever RU-vid comment. Thanks heaps for your excellent videos Quinn and stay safe in this crazy time.

I just want to say that this lesson in parting was life changing. I can part things now I dreaded before. It's all about turning the RPMS down.

After watching every other video on parting I learned a lot but still was having trouble parting without chatter drama. Watched your video and went out to the shop and calmly parted a piece of 1½ inch mystery steel with out a hitch. Thanks for the video and your careful unambiguous guidance. Parting does not have to be sorrowful after all!

Some great points. I was doing my first partings the other day. Unfortunately - I was working on a 2 foot long bar through the headstock - but that end was not confined to center. Registered the 4 jaw chuck to < 1 thou. ...HOWEVER - that was the STATIC position. But in running, the far end was flexing and inducing a harmonic. The cutting got scary real fast - and explained why the facing and turning was so poor. Got halfway through the parting cut and decided to finish with a hacksaw. Was a good learning experience - gotta make more tools for this guy. Finishing off the cut off piece went very well and confirmed the centrifugal force issue. Mine is a 1953 Logan 920 11" x 24". Found one in very nice condition - but stripped it totally down and cleaned, refined, replaced and painted. And it still works, ... LOL. And as you said in a video - one needs to take the size and weight into account. I am working by myself and moving this around and getting the legs under this 700 pound hunk of iron required some real jig work. Enjoying your excellent tutorials...

This is Tina Belcher all grown up as a machinist. Love the vids good work.

Great video Quinn. You are the first person to mention that a shim can help with the flat and t parting blades. One thing I have done in setting the parting blade height is to adjust it to the part that was faced off as it shows the dead center of the spindle. The reason I have done that is that my progressive bifocals don't cooperate when I try to get my head in the right position to align the tool with the live center in the tail stock. Thanks again for the great tutorials. I have been making chips for a short while and am always picking up some great tips.

With your excellent instruction, I've just managed to part a 1 inch piece of steel on a 7x14 Sieg mini-lathe. I'm on day 4 of ownership of my first lathe and I'd be really stuck with out your excellent videos. I'm so grateful you take the time to create such clear and informative content.

Great video and explanation. Parting is the scariest operation for a manual lathe particularly for a beginner. It is a black art. Thnaks for sharing.

i know it's a recurring comment - you're very good at explaining things - that makes you better than a teacher, and more like a machining coach.

Believe it or not but you made my day today. This video series are invaluable. Keep doing so well.

Parting is such sweet sorrow!? LOL! I’ll see myself out now. 😆

Thank you for another excellent video, that shim hint was worth the price of admission for me. :)

Hi Blondihacks, you are obviously a very knowledgeable machinist.As an ex auto lathe setter we always ground a slight angle to the face, it is a single point tool after all not a form tool. Try it you might be surprised.

This is a great lesson. I’ve blown up a parting tool before. Not only is it very noisy, but scares the daylights out of you. After this lesson, no more scary parting. Thank you Blondie!!!

I simply adore watching interesting, engaging and passionate teaching on EVERY subject.

I know this is an old video but this had the most helpful tips I've ever encountered on RU-vid. Thank you

"Your rigidity has to absolutely be on fleek" 😂

I know very little about machining and the more I watch of this series the more impressed I am. This is just the sort of thing someone like myself needs to get off on the right foot. Occasionally you do refer to something you haven't fully explained before (e.g., the compund - what it that?) but I can figure that stuff out from other sources. Thanks for the excellent videos!

The best parting tool for the job is always the one that isn't broken!!

I’m very glad that the first thing you mentioned was USE A FACE SHIELD. You never know in that operation if you’re going to get a permanent part, or unexpected nose job, or worse.

Thank you thank you Gwen! I've done parting more than a few times... but I watched this because I don't know what I'm doing! Now I feel like I do. Thank you so much! One of these days I'm going to watch your threading video again and try that for the first time.

This video series is one of the best of seen on this topic. Thank you for making these!

The shim behind the T-blade! I hadn’t thought of that! I’m so sure that neglecting this has been the reason for some of my... um... ah... well, let’s just say that my blade stock is a bit shorter that it used to be. :-) Thanks for sharing this info!

You have a lot of great tips I wish I'd learned years earlier. You point out that the cutting edge has to be perpendicular to the parting blade to prevent side thrust making it curve and bind, and separately, that some tapered parting blades have a top rake. It's been my experience that the top rake provides a side thrust that makes them tend to bind, and kaboom, hence my preference for the t-shaped parting blades you use.

After watching this one a few times and having the parting blade fly out of the holder. Made some adjustments to the holder as the blade didn't stay put. Think I got it now, parted off a couple thin discs with no issues. Thanks Quinn keep those videos coming

That was very thorough, well done! When I first got my small cnc lathe some fifteen years ago, I used to avoid parting by buying blanks cut to length. Then a tool company rep told me I should be parting off in the lathe to save the cost of having my material cut up. This crazy man was talking about parting at 2000 rpm! I had not experienced insert parting tools before and what a difference. I routinely part at 3000 rpm in brass and aluminium. Carbide parting inserts do not jam up on the sides as they are wider at the cutting edge than any where else. The shape of the cutting edge is designed to create a chip that is narrower than the groove so they do not tend to jam in the groove. The insert I commonly use has rake of 30 degrees which is great for small lathes as it reduces the power required for the cut. Even in my centre lathe which is much larger and slower, the same tools still work brilliantly. There is no way, I would even consider using HSS these days. Can be more expensive than HSS, but well worth it for myself anyway.

I learned so much from this video. You are so articulate. just wow.

Thanks Quinn I may actually try parting agin, having had the parting blade explode a couple of times was more than exciting. I think I now know where I went wrong, everywhere. Great explanation

This is great! I just burned out a belt on my little lathe this morning doing a parting operation. When a replacement belt arrives i will try again following these directions, thank you 😄

Thanks very much. Your attention to detail is fantastic. Your delivery is excellent. I think this is the best video I have watched on this subject, and yes, I have watched many.

I finally find an amazing machining tutorial series. Now... if I could just afford a lathe and mill!

Thanks for the video. I've "only" shattered one parting blade, so far, in the 3 years I've owned a lathe. It taught me to be a lot more careful in my setup. Coke cans are my usual shim stock, .004"+-, I'm cheap!

As someone brand new to this I really appreciate the way you go through the basics.

Thanks for the help I need. your videos are fantastic. I have a lathe thats older than Moses with babbit bearings but I love it. My stand up bracket on my portable band saw helps every time. lol.

Great vid. Wish I had seen it when I was learning at a machine shop school. I was instructed on the parting operation. There was some difficulty positioning the tool in relation to the work. The instructor instructed to extend the angle cross slide to get more room. Half way through the operation the angle Cross slide broke in half. He said he should not have told me to do that. We all learned at the expense of the lathe. I never did parting that way again. I guess that is why the call it school. that was 40 years ago.

I am thoroughly enjoying your videos on Machining. You are very experienced, and a great teacher!

I just started working with a lathe and this video is so very informative. Thanks for sharing the knowledge. In my brief experience, the biggest contributor for problems is tools that aren't sharp enough. For woodwork I depend upon razor-sharp chisels and the lathe tools are no different. There's a jig for sharpening chisels on diamond stones. I think I'll make a rolling jig to sharpen my parting tools, and maybe some of the other tools, on those same diamond stones.

Thanks for the lesson after i had the experience, new gears and parting blade on order. No injuries.

Don't underestimate your ability as a machinist, you are expert in my opinion.👍

Thanks for this, very well presented, all these little tips are way helpful, things I have not even thought much about, just hearing them sticks them into my mental tool box. I'm a little less horrified by parting, especially in my large Goodway lathe I'm rebuilding. Maybe next time I won't resort to the hacksaw in frustration.

This is your best technique video. One thing, I have one of the cheap 7x14 lathes, but it parts pretty well AFTER I got my setup dialed in. It's a cheap lathe so it took a little work, but it was worth the effort.

I now announce the arrival of any anticipated event with... "Yahtzee!" No one knows why, but I do. Thank you, Quinn!

Excellent, -- Clear, precise, articulate. Brilliant, thank you.

Hi Quinn, I do quite a lot of parting on my Harrison M300 and it's in good condition. Everything single thing you have said here is so valuable for beginners. However, a couple of additional things that I do:- 1. I use a height gauge to set my tool heights when it really matters, like parting off. (I actually keep a budget model permanently set rather than keep unboxing my Moore & Wright beauty). Worth noting is that the top face of the cross slide needs to be a consistent good surface, clean and undamaged, alternatively is the method of bringing the tool tip in contact with a straight piece of shim against the side of the chuck, even a couple of thou off of centre will see the shim be 'not vertical'. 2. The second thing I do, particularly with larger diameter stock is to use a travelling steady. It prevents (or should if set right) deflection and saves wear on the spindle bearings. 3. If I have a deep cut to make (large diameter) then I start the blade not extended to it's fullest depth required and extend as needed. (mine are Dixon toolholders so blades are 'flat' not generally angled upwards. I agree about hand feeding, it gives most feedback even though my machine has very slow feeds available I always have my foot on the emergency brake bar as that is a real instant and total stop of the spindle, the other hand is on the feed engage lever ready to drop it out.

Just saw this video....Really great information as I just had some problems on parting off custom size flat washers.Your help saved the day for me.

For small hobby type lathes a back tool post really helps due the improved geometry where the cutting forces are directed down towards the lathe bed rather than lifting the tool away from the bed when parting from a front tool post.

Gracias Quinn tus enseñanzas son oro para mi

Holy crap Quenn, your awesome girl! Just found your channel and impressed with your videos and the ton of information you seamlessly pack into them. You really know your stuff and offer a fresh new alternative to channels like mrpete222 and This Old Tony. Soooo, congrats to you and look forward to more of your fine work. Booyah!

Worth adding for carbide cutting tools : - cutting speed is much higher, like double the rpm for hss - pushing in harder is a less failure prone option : the chipbreaker has to kick in so your chip folds up a little - rubbing will kill your tips in no time - when your carbide tip breaks, make sure NONE of the shrapnel stays embedded in your stock or your next tip will break immediately

Congratulations ! this is a very very good explanation on WHY I was having problems "parting off" your in depth explanation did not fall on deft ears ! THANK YOU ! though I heard all this before the important thing is Parting is Picky work on a lathe Tighten the gibs and sharpen the tool ! and don't be in a hurry ! way to go Blondy !.....Bob...

Yes watched, listened, learned - 3 top tips speed, lube and set-up. Just parted 40mm (1.5 inch) dia blue steel on my 8 x 16 mini lathe - previously I broke a high speed 12mm parting tool on brass!

A very well explained and demonstrated video as usual Quinn. I fully understand it's a complex subject and you can't hit every possible scenario or example without a video taking forever to film and watch. At some point in another video it might be worth mentioning that fully parting off with the end outside the chuck supported by a tail stock center is a REALLY bad idea. I watched one YT video last year where that was done with a very long shaft because the person doing so didn't know enough to not even attempt it. You can of course part most of the way through that way and finish with a hack saw. Oddly it must have been beginners luck because it some how worked for him without any drama. If I tried that just once at the minimum the head stock would probably get ripped off and body appendages I highly value would be thrown every where. I always recommend one book no matter how much experience a person has including professional machinist's. The Model Engineer's Workshop Manual written by George H. Thomas. And yes it is that good. The Ebay reseller bandits all want a fortune for it. Cheapest is to order it direct through Tee Publishing in the U.K. and they ship world wide. He goes into great detail about parting on the light weight Myford Super 7 lathe and logically explains just why the solid rear mounted parting tool position works so well. One side benefit is that other than for large diameter work where it might cause interference the parting tool is always ready to go and doesn't need any tool changes or setting up. The books full of tips and tool making designs for various lathe additions that are usually only seen on the higher end tool room lathes such as his lever operated threading tool holder, or the same for the whole top slide for single point threading like the Hardinge HLV has. There all designed for those Myford lathes. But for anyone with enough experience none of them would be that tough to redesign to adapt and work on other lathes. The whole point of those rear mounted tool posts beyond the extras they provide in that position is there very rigid and remove the flimsy top slide from the issue. One of the main reasons I bought the same lathe as you have is due to Mr. Thomas's writings and that tee slotted cross slide. Afaic his well thought out design for a between centers boring bar is worth the price of the book just for it.

Wish I had have watched this 3 days ago! I just got a new lathe (bit bigger than yours), my first lathe, and had a parting blade explode in my face. Luckily I was wearing safety glasses but it left a little cut on my forehead! Now I know how to avoid it. Thanks, also, great series! Right on topic for me at the moment :)

Quinn I find you do a great job on lots of detailed information on all your videos. Well done.

Recently found your channel as I was looking for videos on model steam engines. On my similar lathe I was noticing flex in the compound which caused trouble while parting. My solution is placing a machinist jack on the cross slide and under the tool holder. This helps reduce the flex. I’m tempted to remove the compound for this reason. Thanks for all the effort you put into the videos! Jim

Excellent video. Good production values and great advice. I've watched a lot of videos on parting, and this is probably the best.

Thank you, this had so many of my issues addressed. You rock, keep it up.

28:38 what I did in high school is, made a slot with a single point tool, then with a slow rpm and a rag or wood on your ways, start cutting.

Nice descriptions of various parting tools. Snapped off quite a few in my early days.

i just got an old lathe artec C1 . with tour help i got it up and running werry well. thanks from denmark Blondie .🤓

Wow, such a crystal clear explanation. I'm ready to give it a try again, thanks!

Dead nuts on. Nice. Is that metric? I guess I have only been doing 10 things absolutely wrong and 4 other things just slightly wrong. Maybe I won’t need to stand behind my tactical bullet proof swat shield anymore when I part. I thank you, my spleen really thanks you. If I had a 100 dollar bill, I would send it to you directly. Thank you so much for this great video.

Thanks Quinn, great video on parting. I have used it for training my apprentices. Fantastic educational piece.

Fascinating, educational, and enjoyable to watch (I love your sense of humour!)! I don’t even have a lathe, but still love absorbing information about machining in general. A brilliant video, thank you Quinn! On the point about using a powered cross-slide, I guess the other disadvantage of that is you presumably want to start going more slowly the closer you get to the centre of the stock as the surface speed will slowly be reducing - that, or slowly increase the rotational speed. But either way, it seems hand feeding is the best approach, for a hobby shop machinist at least.

Thank You! Very informative!! Small details make a huge difference. I will put them in practice when I attempt parting..

Thank you for all your great teaching videos! Your the best!

Parting is such sweet sorrow.

Thanks Blondie Hacks. Could have used this video years ago. I have painfully learned these techniques through trial and error. Wish I would have watched this video first.

I was making a part out of 303 stainless and was about to part it. I thought, "I better go see how Blondihacks does it again or ill blow this thing up and have to start over". Your video was perfect. My old Southbend 9c parted that dude like a champ. All the extra care in set up and particulars really helped. Thanks again!

Had to watch this over 2 days. It was well worth finishing. Great tips

Very good vid. Probably the best info and practice for a novice and rookie. To this day I still have a huge hate for hss part off tools.

Your video are AWESOME!!! Thank you for all the details!!

I just got an accusize parting tool and I had all kinds of problems broke n insert and it was chattering like crazy but you anwered most of my questions thank you i will correct my mistakes and try again.

Thanks Quinn

Gosh this video made me nervous! Love the series!

Excellent video as always. Keep up the great work.

to do parting on my 7x14 chinese mini lathe, I had to improve a lot rigidity on all slides and a lot of trial and errors. Now I can part stainless steel or white steel with a 2mm wide hss flat rod, grinded as needed. many thanks for the nice explanation

I kept my first small lathe I just couldn't part with it LOL Seriously great info again!