Ive been doing case hardening Commercially for the past 20 years, sorry if I did not articulate that well enough.
When I decided to offer CCH as a shop service, I spent about a year figuring it out. I would take mild steel blanks (SAE 1018), grind them on the surface grinder to ensure that they were flat (+/- .0001) then case harden them adjusting the variables one at a time: Hardening temp, time, wood bone ratios, quench tank size, O2 levels, drop distance, quench water temp etc.
I did quite a few drops, as many as 3 a day. After each quench I would check for colors, hardness and warpage.
I also tried some of the secret recipes:
Hoof material: I have a small horse ranch, so Im somewhat familiar with hooves as I have to clean them and trim them quite often. The sheer amount of garbage that gets imbedded into the hoofs: rocks, nails, dirt manure etc. they are nasty, and no good way to clean them. They are also made out of keratin, same as hair and fingernails.
Leather char what an abomination: I once made some specialized tooling for a custom saddle maker, as payment I asked for some scrap leather, I ended up with two 55 gallon drums full of heavy, saddle grade leather.
There ae several ways to tan leather, Chromium, tannic acid, etc. All add chemicals to the leather. Or you can opt for untanned rawhide (think dog chew toy).
To make a short story long, I decided to char some leather; I took a tightly packed shoe box sized amount and put it in a crucible and cranked it up to 1600 F. Thats a day that will be etched in my mind forever The smell and smoke was horrendous, think that burning hair smell on a massive scale. Adding insult to injury, leather doesnt carbonize in the normal sense but rather melts. What I found in my container, was not powder or leather that could be crumbled, but a substance that resembled hardened lava that stuck to the interior of the crucible. Once I chipped the majority of the charred leather out, I had to sandblast the remainder out. So, for a shoebox sized amount, I ended up with about cup of leather char.
In the end, I did try the leather char, the result No better or different than standard bone charcoal.
Hooves/Horns (cow/horse) too dirty, and made of keratin.
Ivory, too expensive and made out of tooth material very sililar to bone.
Powdered Anthracite: simple coal dust.
Leather have fun with that
Respectfully
Mike
