Thread: Work Hardened Steel Is No Bueno

Just a quick post to celebrate what has been my vexing bane for the last couple days....

I forged out a bit of San Mai - High carbon core (1095) with stainless cladding. (Which by the way I have become quite good at, if anyone would like to know my method, let me know and I'll do up a full picture thread of my step by step process in a couple weeks when I run some new billets through the forge) Anywhoo - back to the celebration at hand!

So, I forged out this San Mai billet. Now, this time round I thought it would be fun to go thicker on the stainless, thinking that I could grind down to a more exact spine thickness. Like some gents, I overestimated the size... of the stainless stock. Came out of the forge and press darn near 1/2" thick. Much grinding would be needed.

Now, I have no idea how much stainless fun you folks have had, but there are some interesting properties to stainless. It is extremely hard on your abrasives (which is why it makes for a great cladding. Hone wear is minimal on the spine) and damn does it ever get hot while you work it.

I anneal my billets after forging, however, when taking off that much stainless as I had to, I apparently heated up that high carbon core pretty well. During the grinding, as it got hot I quenched it and kept going. After finally getting the razor shape cut in and fully flattened, twas time to drill the pin hole. I choose a traditional 1/16" for this. And that was when my trouble started...

Turns out, just the heat created in the grinding of the stainless and quenching to cool hardened that core. Really. Hardened. The. Core.

I ended up killing five drill bits on the press. Got so fed up I threw it back in the kiln, and re-annealed it. Presto! #6 drill bit finally got the job done!

I'm honestly shocked that the grinding could have heated up that 1095 enough to harden it. But, at least now I know once this piece goes through heat treat that blade edge will harder than drill bits...