I would love to know this process, how you will use them?
I will surface harden mild steel parts and give frizzens more carbon by packing parts in charcoal, surrounded on all sides and closing the box and heating in the forge till bright red. I’ll keep it going for about 45 minutes. I include mild steel tie wire that’s 1/16” thick as well. From the forge the box is taken to a bucket full of water and the lid removed and the contents dumped in. Great care for safety is needed. If all goes well the parts will be hard as glass on the surface. The tie wire which is normally very flexible will snap when bent in the hands, indicating it’s been hardened deeply. That’s my test for success. Parts are then tempered as needed.
It takes a deep fire and plenty of coal. I don’t try for glorious case colors but often get some blues in the process.
Lock parts can be made of mild steel and when case hardened this way, work beautifully without wear.
I’ve used thinner boxes before but they don’t last many uses.
