On Thu, 8 Aug 2013 08:12:16 -0700 (PDT), Bob La Londe
wrote:

I am sure you are familiar with them. The flat black (sometimes otherwise coated) wrenches that come with a lot of power tools for changing blades, bits, discs, etc. They look like they are stamped out of sheet. I am certainly not going to make a stamping die for one wrench, but I am sure I could cut one out of flat stock on the mill when I need one and a regular mechanics wrench won't fit. The thing is I don't know what steel to use.

How about an inexpensive alloy that might be easily heat treatable. I don't think surface hardening would help for a wrench or a spanner as the cross section would still be softer, but maybe somebody who knows better could speak up?

Those things are almost always made of plain carbon steel. 1070 is
common for tools and other odds and ends that need strength with a
moderate amount of ductility.

You'd be suprised how *few* things that we think of as high-strength
are actually made from alloy steels. For example, the piston rods on
shock absorbers and struts: Plain carbon, 1070.

Quality wrenches often are made from a proprietary grade of
chrome-vanadium alloy. But the advantage in most practical uses is
slight.

--
Ed Huntress