Thank you. This was a very clear, easy to understand and thought provoking tutorial. I was a blessing to be given the opportunity to do some lateral thinking about this processing.
Very interesting, very cool, seems easy enough to do, and I am thinking of doing this on some small gears made of mild steel, thanks very much for posting !!
Very nice! Thanks! I recut the dogs on an old gear and likely milled into the case somewhat, so Im going to give this a shot, hoping it will improve at least the freshly cut areas.
Hi nice to learn and see how you case harden your metals. Thank you for sharing your process to achieve the task at hand. We like your channel because you machine and work with small parts, this is as well what it is we do, so we relate well with your efforts. Lance & Patrick.
I recall Clickspring doing an in-depth video about case hardening steel to make crude files. This is certainly a much simpler method for the home shop. Thanks
Thank you for this video. A friend of mine made a mild carbon steel knife and only realized afterwards that heat treating it to harden the blade might not work. I'm not sure if case hardening will work, but as a hobbyist I felt it worth a try.
It might keep an edge through hard use for a month. Case Hardening will still dull noticeably faster than HCS, but be noticeably stronger than mild steel. Mild Steel was and is harder than all other forms of metal man had made for the last three thousand years before it. The knife you made would be a kings treasure two thousand years ago.
Hi. I'm not sure if it's still of interest to you, but here are two videos that show both the process and the result you're interested in, penetration depth: m.ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-V_Mp1fNzIT8.html m.ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-aFqdWXDZiq4.html
I'm not a knife expert, but if you sharpen a case hardened knife, you will grind through the hard case into softer metal underneath. Knives need hardness through the blade not just on the surface.
Wouldnt this harden the entire piece of metal? I thought case hardening was only the outside layer but if your heating and quenching the whole part should make the whole piece hard?
Thanks for the vid, I live where you can only buy mild steel and no case hardening powders available, i have had to make a 20''' lawn mower blade, and will attempt to case harden slightly to stop it bending and hopefully keep the knife edge longer it buy using charcoal powder , any thoughts on this will be much appreciated. thanks.
Brian David Hi, charcoal should work. I don’t think case hardening will affect the bending strength of the steel though. I’m not sure if it’s standard practice to case harden lawnmower blades - mine is normal mild steel and I just sharpen it on the bench grinder occasionally. But why not - would be fun trying! Cheers.
Thanks for your reply I think they are made from some sort of stronger steel as i tried to straighten one under a press with minimal success it sort of just sprang back, the reason was that the jerk i left it with for repair apart from the fact he flattened out the wings it was now bent. I have made 2 new ones and used a clay barbecue with a fan blowing on it to heat red then bent the wings up and have ground the knife edge. wish i could post a photo. yes i could sharpen the old one easily but it became so worn, and i cannot buy a new blade anywhere. I am going to give it a go today at least it may prevent it from rusting @@MetalMachineShop
I guess you would need a good reason to make, rather than buy, in the first place. You would need quite a bit of tooling to start with. The chain plates would probably best be stamped out or laser cut, etc., but I suppose you could cut them out by hand. You would need a jig to drill the holes in the plates at the correct spacing (if not already stamped out). Pins would need to be hardened and profiled so they don’t pull out, and pressed into the links. Finally rollers could be made on the lathe and would also need hardening. You would need a certain amount of expertise in all these areas to ensure success, particularly if personal safety is involved in the chain’s application.
@@MetalMachineShop something a bit like a Gunter’s Chain but a bit simpler. The “links” would be very thick, maybe 25mm or higher, with a goal of having the greatest resistance to angle grinding on the market but also to be the same weight or lighter because there is less material with long straight rods with loops on the end instead of short oval links like a normal bike/motorbike security chain
I get it! Sounds like a neat idea. The end links would need to be welded to the bars I guess. You would struggle to stop anyone with an angle grinder, even very hard steel is easy to grind through; in fact softer material like aluminium can be more difficult to grind, but it depends on what sort of cutting disc you use. Hardened steel should defeat a hacksaw and be harder to cut with bolt croppers. Whatever, the thicker it is, the longer it will take to cut and it might be thick enough to be unable to fit between the jaws of bolt croppers.
@@MetalMachineShop thanks Yeah, from what i have researched, nothing is angle grinder proof. The biggest motorbike chain on the market is the almax VI which has 25mm links and weighs a ton. A youtuber cut through it in about 14 minutes under perfect conditions. My goal would be to either get a lighter chain but with an equal grinder attack time, or haceva chain the same weight as the almax but get much greater grinder attack time. Preferably id like lighter weight AND greater grinder attack time. From what i see, to defeat a chain you need 2 cuts with the grinder on one side of the link. In some ways the material on the uncut side is wasted . Well, not really as its needed to create a closed link, but i wonder if there could be a more efficient use of materials. The first cut of a link with a grinder seems to be the longest , say 10 mins, but they second cut is much quicker, say 5 minutes. i read that its because the metal heats up and has room to expand now there is a slight gap ftom the first cut. And also the disc doesnt bind up. So i would rather use all the material of one link and form it into a single rod, which would only need one cut to get through, but would be so thick that it would give a longer angle grinding time With multiple links of a chain, it takes a lot of links (material) to cover a distance, so again, a lot of material is wasted, when a straight rod could get from A to B much quicker and more efficiently. I dont know how long i would make the rods/links , but i guess it would be a balance between being portable yet long enough to save weight. Maybe 2 feet rods as a rough guess. There is actually a company i found that has made some similar to my idea.
Much more difficult to significantly carburize stainless, since the chromium, nickel and so on tend to "sweat out" into a thin surface layer that blocks the carbon from entering. However the stainless steel baskets we use in the furnaces do tend to form a visible, deep case, and eventually become brittle, over many hundreds of hours at temperature, over years, so it is technically possible.
First of all, thanks a lot for the video, it's easy to understand and probably the simplest demonstration I've seen. I have a question about quenching: I know that, for example, quenching in oil is preferable for making spring steel. I've watched a couple of videos about case hardening and everyone used water. Is water preferable for case hardening, and would quenching in oil produce different results?
Hi, as far as I know using oil would make no difference. Quenching is about rapidly reducing the temperature of the heated metal in order to preserve it’s crystalline structure. Both oil and water can achieve this. I don’t think the fact that it is oil rather than water makes a difference at a chemical level. I think the bubbling as water boils can reduce the speed at which the temperature drops; this doesn’t happen with oil. Water is cleaner and easier than oil. For large parts, oil is probably better and safer as long as it’s not flammable.
@@MetalMachineShop Thanks a lot for the response! If you don't mind, I have another question - how does the temperature affect carburization? What happens if the metal is hotter than red? The piece that I want to carburize looks like a long cone and I'll be using a charcoal forge to heat it up, so it will be very hard to get the same temperature along the entire piece since the tip is much thinner than the base.
@@blasty137 Hi, that question is stretching my knowledge a little. I suspect that heating beyond 'red' may adversely affect the results and impact on the properties of the steel. However, if the part can be steadily heated for a reasonable period, it should be possible for it to achieve a uniform heat despite the taper. Overheating is unlikely to give satisfactory results. Trial and error would be an option or further reading into heat treating.
@@blasty137 From memory over heating the steel will result in softening or Annealing the object. The various colours that an object changes to as you heat , blue, straw, plum, cherry red, bright red and so forth will lend itself to different results - Sorry - this is from the deep recesses of my memory as an apprentice copper smith some 40 years ago
Fascinating! I do have one question though: does the carbon coating add anything to the OD of the part? Or does it really penetrate through the surface, leaving the OD as it was when the part was machined? Thank you for sharing your knowledge!
I don’t think that the carbon itself appreciably changes the diameter of the part as it penetrates the crystalline structure of the steel. However, it does result in surface scale that needs to be removed. The heating process can cause the metal to distort. With a decent depth of surface hardening it is possible to grind the surface slightly to remove distortion and achieve precise dimensions. These are unlikely to be a problem in a home workshop environment though.
@@MetalMachineShop Thank you for the detailed reply. I would need to apply this technique to harden the valves (camshafts and crank shaft too, of course), of the Schillings V 8 that I am currently making. I will bare this in mind, and experiment on my "failed attempts" parts bin. Hopefully, a working engine will see the light of day, at some point. I will surely keep you posted about it. Thanks again!
I don't think you need to bother hardening the plain bearing surfaces on crankshaft or camshaft - just the cams and tappets. The risk of distortion offsets the advantages. Only worth it for an engine that will have lots of use. I would be interested to see how your engine progresses!
@@MetalMachineShop Interesting insight. I will bear this in mind. I will indeed post some of the progress in due time on my own RU-vid channel. It won't be before quite a while though, as there are dozens of other topics in pipeline. I will give you a shout though. Thanks again for sharing your knowledge!
