Normalising

Normalising is a tedious business, so I roped my son into helping. You have to heat the steel slowly to critical temperature, then allow it to air cool, then repeat. On the last cycle I put them into vermiculite to cool over a long period of time. This makes the steel soft enough to file.

Titanium and tagane

It seems titanium is more demanding on the points of the tagane (tagane are the collective name for the types of chisels I am using) I may have to re-heat treat these or find a better material to make them from. The ones I have are high carbon steel but if I want to chisel titanium I may have to get some high speed stainless blanks. Tungsten I think would be too brittle.

When heat treating is off

One of my chisels is going blunt really quickly. On closer inspection, I saw that the edge was rolling which means the steel is not properly hardened. This is probably the result of inaccurate tempering. I'll have to harden and temper the chisel again. It's difficult to get a good picture of the rolled edge but here is my attempt.