On 2/20/14, 6:05 PM, Bob La Londe wrote:
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?

Do a spark test...

http://en.wikipedia.org/wiki/Spark_testing


A bunch of videos are here... But I don't have time to wade through them
right now...

http://www.youtube.com/results?searc...ng+metals&sm=1

Erik