If you are talking about the button catch at the end of the lid on a captured box, that is basically a nail driven into the wood. I forge mine from 1/8" 1095. You forge it just like a nail, upsetting the head. I believe I have just done mine in a vise. You then must file the spike part of the release pretty thing so that it will flex. You want it to flex rather than just move in the wood which will result in it working its way out. I do harden and temper mine like a spring, but I don't think it is really necessary as you aren't flexing it much.
