What you get when forge welding half wrench with a piece of 1070 high carbon steel? A wrench knife! Totaly unnecessary and very weird and funny looking! I bought the wrench for 1€ at a local flea market, un-branded old tool, probably drop forged out of some kind of high carbon steel. It forge welded very well over a 3mm thick and 50mm wide 1070 (aka c70) high carbon steel flat bar. The blade is differentially heat treated with edge hardness between 60 and 65 Rockwell.