Monster Mortising Chisel

My brother the woodworker always wanted one of these. We were working together on repairing a large timber joist whose end had dry rotted halfway of its seat in the brick wall, and the job called for a large chisel and some heavy pounding. He knew exactly what kind of tool he needed (properly, a framing chisel, but I went for alliteration in the title) but they're ridiculously expensive and hard to find these days -outside of the internet, anyway. So since he knew what he needed, and I was in the mood for some smithing, we raided my scrap pile for the steel and set to work making a quick and dirty tool.

We cut the full-tang profile of the chisel out of a (Ford) truck leafspring, which means the steel is most likely 5160. The bolster we build up with weld, and we stuck a section of 1.5" dowel bar (used in highway construction) on the end to be nicer to our hammer faces.
Lacking a forge at work, we used two oxyfuel torches to bring the blade up to hardening heat and quenched in a bath of used refrigeration oil. It's a wonderful (ie: gentle) quenching medium, and it happened to be handy. Then we used the old blacksmith's trick of normalizing on section of the tool, and using the residual heat to temper the tool.
Construction took most of the day. We sharpened it and added the handle scales that night. We'll see if my brother ever gets around to exchanging those dirty pine scales for something classy.

In all, the chisel measures eighteen inches long, nearly three inches wide and half an inch thick.