I believe we are told not to use the CBN grinding wheels on anything other than hardened tool steel. I know that I shouldn't grind steel bolts, or brass, or copper because it will clog the CBN wheel and render it useless. I know that the turning tools I bought over the years are various HSS, except for maybe the very first set that came with a lathe package back in 1970 or so. But how can I know about the hardness of various steels that I may come across? Is there a simple way that a layman can test it to verify?