"Bob La Londe" wrote in message
...
I've got a piece of mystery steel about 2' x 6' x .78". It was
given to me by a friend when he was moving. I have a couple
projects for it that are going to require machining. What would be
the best guess for the alloy to machine conservatively but without
killing cutters? A36? 1018?

I check scrap steel with an old file or hacksaw blade before risking a
bandsaw blade on it. You can calibrate your touch by filing 4130 or
O-1 or whatever else you have that requires extra care to machine.
jsw