Making Case Hardened Gears - Heat Treatment Oversimplified

G'day everyone,
In this video I will be case hardening a gear. gears are a good candidate to be case hardened, due to the large amount of wear that will be encountered by the gear teeth meshing. I will case harden the outside of the gear in order to harden it and increase the life of the gear. I will also be experimenting with a piece of EN36A case hardening steel, which has higher tensile strength and hardenability than normal low carbon steel. I will also briefly touch ion hardness and hardenability in heat treatment and do a test using some 1045 and A2 air hardening steel. I hope you enjoy the video.
#machining #gearcutting #heattreatment
Timestamps
0:00 - Intro
1:11 - EN36A Case Hardening Steel
3:25 - Heat Treatment Hardness vs Hardenability
7:07 - Cutting The Gear
8:02 - Case Hardening The Gear
11:27 - Cleaning up The Gear and Testing The Hardness

[@DoRC]

One thing to keep in mind is to test the gears that you're going to be meshing with. If you make a really hard gear and it meshes with a really soft gear You're going to end up killing that softer gear pretty quickly.

[@tullgutten]

Unless the hard one is super polished so it has no sharp edges at all. If it is sharp it will indeed powder the other one 🤣

[@DoRC]

@@tullgutten Even if it's not sharp edge it will still wear the softer metal much more quickly.

[@R9000]

Hey, at 10:43 you say "slightly less than 0.1mm", but if I'm reading those calipers right it looks like slightly less than 1mm. By eye that would mean the gear teeth are hardened almost all the way through. Was that the intention? Great video by the way! I really appreciate someone covering case hardening like this, it's something I'd like to try at some point too.

[@artisanmakes]

Oh yeah that would be right :)

[@jmtx.]

Thanks for the great details going into the whole heat-treat process. Awesome work!

[@arthurmorgan8966]

I like your storytelling style and how you explain concepts. Well done. 👏

[@slyder2k6]

You spent half the video talking about the material before you even started making the project. And that my friend is one of the main reasons I love your videos! The are informative and knowledgeable. And you take the time to try and inform on top of the entertainment. Keep up the great content!

[@davidrule1335]

Yes, and that's why I like Mr. Pete so much. I also like his stills at the end.

[@TalRohan]

He also does it in an interesting way which helps immensely....I've some really informative videos on other channels but so snore zzz.

[@howardosborne8647]

As you point out this is probably way overkill for lathe back gears as some lathes like South Bends have back gears made from Mazak and they last many decades. None of the back gears or screwcutting box gears on my Harrison L6 are hardened in any way. They are very soft steel very much like a leaded steel but none show any signs of wear despite being in use since 1964....Great educational video about hardening all the same.👍

[@JugglesXP]

Always love your videos. You truly are an Artisan.

[@GavinM161]

EN32B was what we used for case hardened cams. Probably should have put the charcoal through a coffee grinder or sieved it to get more even charcoal grains.

[@SonofTheMorningStar666]

Highlight of the week.

[@MattysWorkshop]

Gday, great video, I’ve never heard of this material before, thanks for sharing you knowledge mate, cheers

[@yodasbff3395]

Very interesting, thanks for the information 👍. Good video.

[@yeagerxp]

Well done . Informative 👍👍👍. Thank you for sharing. Be safe🇨🇦

[@Smallathe]

Very cool DIY gear and hardening :)

[@whitecaps775]

Sweet info here, glad to learn about another material to add to the brain storming. Thank you

[@nardaoeletronica]

Excellent job.

[@landroveraddict2457]

We all need a friend like you.👍👍💙💙💛💛

[@abdeljalilpr2033]

Very important video.. respect from Morocco

[@Alan_Hans__]

Very nice work. Work smarter not harder.

[@amitattafe]

Hmm nice to see workshop experiment in house.. Metallurgy knowledge is awesome. How you cut the gear from saw by hamd with perfect hands was too cool....

[@TalRohan]

I like that case hardening tecnique ...adding sodium carbonate makes a really big difference to the outcome....wondering if its worth using EN36A for a hammer...perhaps not lol .. Thanks for sharing

[@davidrule1335]

13:05 You mentioned overkill. The hole video I was thinking you may wanna make two hardened gears. So you could make a fixture to run them together with lapping compound. Any machine marks on the hardened gear will wear out the mating gears in your friends project.

[@artisanmakes]

If it's anything like my lathe, it will have some spacing rings or washers. It it's a probkem, I'll certainly hear about it

[@KallePihlajasaari]

@@artisanmakes I think the suggestion was to use a second gear to lap the working faces of the teeth. Two identical (involute) gears correctly spaced should work as grinding partners to shape the other gear to exact involute profile. With case hardening you prefer not to grind them much unless you have precision machinery but lapping is a acceptable option.

[@davidrule1335]

@@KallePihlajasaari Yes that is what I was getting at. Transmission and rear end gears go through a lapping process to reduce noise. A rock hard gear with tool marks may shred it's mating gears.

[@davidrule1335]

@@artisanmakes I'm not picking at you. I watch and love your work. Just remember you heard it here first. lol

[@Chris-bg8mk]

Good Job, and well explained! I once made some simple lathe form tools from 1018 mild steel, then case hardened the heck out of them. Tempered slightly so they wouldn't chip or shatter, they did the job admirably. Even cheap cheese grade steels can be case hardened and used as tools or parts if they're not required for production quantities.

[@ShaneGadsby]

@8:17: I see your Bunnings also only ever seems to have the XL black nitrile gloves 🤣 Great video as always mate!

[@adamfaris9375]

When sealing the canister with kiln cement, how long do you wait for it to cure before heating in the kiln? Also great work on this topic and thanks for the videos.

[@artisanmakes]

A few hours in the sun or overnight is usally enough

[@jozefnovak7750]

Super!

[@DanielDerosiee-cn7pj]

Good I subbed.

[@MatrixCoreteam]

Your explanation of hardenabiltiy is good. The surface will transform quickly, but the center of the cross section will take longer to cool. A higher hardenable steel will allow you drop below the ferrite and bainite start temperatures and get to the martensite start with a slower cooling rate. However, I doubt you could see a difference in surface hardness between this steel and a 41XX steel at the surface. In fact, with this small of a cross section I doubt you would see a difference in your core hardness as well. I am a metallurgist for a farily large carburzing heat treat shop. We use many different alloys of steel, 41XX, 86XX and 43XX. The 43XX would be similar to the steel that you used but less hardenable. Less Ni but with some Mo. When carburized under the same conditions, the 43XX and 41XX are indistinguishable at the suface. With this small of a section we would not see a difference in core hardness as well. Good work though. We do gas carburizing, i have never looked at a pack carburized part under the scope to see just how quickly it takes on carbon.

[@patrickosullivan4354]

When I heat treat chasing tools I use Dove bar soap as an oxygen barrier in the last stage when drawing out the temper. Cheap effective and easy to clean

[@artisanmakes]

Never heard of that one but I will definitely be giving it a go. Cheers

[@HM-Projects]

Interesting, I would've thought 4140 is more suited for making gears and high wearing parts like shafts. Given it's cheaper a better choice perhaps ?

[@azza9575]

Contact special piston services, they use that en36a in the pistons they make for wrist pins

[@DiipsRatsAirsoftPortugal]

shoudldnt the lathe gear have a keyway slot? good teching once again, thank you

[@artisanmakes]

It's an idler gear so it doesn't need one. Cheers

[@zerocool9774]

To protect parts from scale during heat treatment, if you will use water based solvents as cooling liquid, you can use powder boric acid. Clean part with alcohol or any solvent to remove dirt and residues of oil etc, then heat it with a blow torch a bit and sprinkle with boric acid. Repeat untill whole part is covered. While cooling, boric acid will break by itself, making cleaning much easier.

[@artisanmakes]

I'm sure that works too. It's probably not too different from the potassium fluroborate based flux that I use. Cheers

[@zerocool9774]

@@artisanmakes yes, it works, im using this method for heat treatment of custom cutting tools (reamers, taps etc) im making. Boric acid just a bit easier to clean and, in my situation, its more accessible.

[@MrDuffman83]

Nice video men. One question and one ask. What software do you use to design your projects? And it would be nice a video about making our own gear cutters. They are very expensive and you need a lot of them!

[@artisanmakes]

I use mainly Solid works and occasionally CATIA. Mostly because that is what I have used for the past 10 years. Fusion 360 also is great but I personally prefer solid works. I don't know too much about making gear cutters, but Chris at click spring has a whole patron series about making gear cutters.

[@MrDuffman83]

@@artisanmakes thank you!

[@hobtink]

Isn’t making such a hard surface more likely to create extra wear on lesser hard surfaces of interfacing gears?

[@artisanmakes]

It will but it's meshing with steel gears so they all should hold up for a good Humber of years, and they can always be tempered back if needed

[@aliwilliam-js4iv]

Is it safe ??

[@romankhan9313]

can i case hardened mild steel? how hours could take to reach 1mm 60hrc?

[@artisanmakes]

Yes you can case harden mild steel. Time varies depending on the type of carburizing and the temperature, but with my method, using charcoal and sodium carbonate, 2 hours might get you a 1mm case depth

[@troyam6607]

seems the material is equivalent to 3310/3415 or E9315/9310

[@artisanmakes]

Not too familiar with that grade, but after looking it up, it seems to be very similar to En36A

[@troyam6607]

@@artisanmakes En seems to be the British grading system and ASIO is the American version so 4140 1045 ect

[@rickpalechuk4411]

Wouldn't be a proper video without the hacksaw Cheers

[@josecarlospoggian149]

👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👍👍👍

[@jfirebaugh]

Is there a risk of metal gears causing the plastic gears to wear out more quickly?

[@FamTech.]

I think so, his mate wil just call him agan🤣

[@r2db]

The softest material is going to preferentially wear, so this will cause wear on unhardened steel, steel will cause wear on brass, brass will cause wear on plastic, etc. In some cases this is a design feature, where the cheapest and easiest to replace gear in a mechanism is made from the weakest material.

[@howardosborne8647]

@@r2db That isn't always the way it works out. Often the harder material wears more rapidly than the softer component. This occurs because the softer material is prone to embedding of microscopic particulate and acts like a fine abrasive element wearing down the hardened component. A differential of hardness and softer materials is usually a desirable design element for shafts and bushings etc that run against one another.

[@r2db]

@@howardosborne8647 Good point and I do agree there. I was thinking in a lathe gear train this would be less likely, but if one is doing a lot of toolpost grinding or leaving the side cover off routinely it may be a significant concern here.

[@davidrule1335]

@@FamTech. Read my comment above. It explains a way to reduce that chance.

[@johnathancorgan3994]

7:50 🙂

[@Argosh]

Just make sure he's not replacing an intentionally weak part with this hardened strong monster. Some Gears are supposed to break in order to protect expensive stuff from overload. No use making a gear that will cause the gear case to break.

[@pawekowalski7469]

I've subscribed to your channel for a long time, now I have a small problem, I can't turn on the translation of subtitles to Polish in this video, it also happens on some other channels that I also translated in previous videos, I don't know if it's the fault of youtube or movies. At 13:16 minute, all the subtitles appear on the full screen. greetings PL subskrybuję twój kanał od dawna, mam teraz mały problem, nie mogę włączyć tumczenia napisów na Polski w tym filmie, dzieje się też tak na niektórych innych kanałach które tez w poprzednich filmach tłumaczyłem, nie wiem czy to wina youtube czy filmów. W 13:16 minucie pojawiają się wszystkie napisy na caly ekran. pozdrawiam

[@artisanmakes]

Sorry to hear about that, translate can be incorrect on some videos. Mostly the issue is with KZbin

[@pawekowalski7469]

@@artisanmakes I wonder if you, as the author of the film, can report such a problem, I really appreciate your films and the knowledge you share 👍

[@mk6595]

You forgot the keyway.

[@artisanmakes]

It's an idler gear, the shaft that it goes on doesn't have a key

[@bencesarosi7718]

@@artisanmakes Ahh, that makes sense.

[@RB-yq7qv]

😀😀😀😀😀😀😀😀😀😀😀😀😀😀😀😀😀

[@asdfghjvrty]

Did he forget to put a key way in?

[@Kineth1]

I believe he said this was supposed to be an idler gear. Those don't need to transfer rotational force to/from the axle they're on.

[@artisanmakes]

It's an idler gear so there wasn't a need for one. The shaft that it goes on doesn't have a keyway

[@asdfghjvrty]

Ohh OK. Thanks, must've missed that part.. 😂

[@PatriotPainter]

In Australia or New Zealand, how do people know if someone is asking you to make a gear or a Karate uniform?

[@kenman6721]

don’t ever use water to quench.

[@artisanmakes]

No there are valid reasons to water/brine quench.

[@kenman6721]

@@artisanmakes salt baths yes but pure water no. the reason is simple when cooling with water you quench to fast and it causes all kinds of stress to the metal

[@artisanmakes]

That will all be dependent on the material, its intended use and how it behaves, as per the applicable TTT diagram. There are reasons to quench in water, mostly because they produce the hardest finishes, at least with case hardened carbon steel in a home workshop environment. cheers Also better to quench in brine to reduce Leidenfrost effect. Which can definitely warp parts

[@DodgyBrothersEngineering]

@Artisan Makes do you do odd jobs for other people? I need something made that would be within your skill set, but still very interesting.

[@Knobiks]

0.1 of cm not mm, so 1mm :)

[@artisanmakes]

Yeah for sure

[@Megalomon]

Overkill? I don't believe in Overkill!

[@philip_fletcher]

This is Colchester case hardening their lathe gears back in the 50s(?) kzbin.info/www/bejne/pILEcn6Ldt9-Ztk

[@spam_3320]

yo

[@drewfaulkner2967]

"overkill" you mean future proofing a remade piece.