Oouch hot fingers

But what would "they" know? "They" did not even have YouTube.

The most common cause of the hss getting hot is either the wrong grade of grinding wheel, or it has dulled and needs to be re dressed and sharpened. CBN works very well for hss , but again the wrong grade for roughing out and it all just gets hot. They have cbn dressing sticks as well. When roughing out a new tool I keep it cool by dipping the blank into the water often. When the water starts to bubble or boil, dip again. When the time frame to boil the water near the cutting edge happens inside 10 seconds of grinding, the wheel needs to be de glazed or re dressed again. An open 36 grit wheel is great for roughing out tools, while a 80 to 100 grit is great for the finishing and light touchups. Many just by the finer 40 or 60 grit and try to make that 1 wheel do everything. I only make form tools from hss or tools that the standard shape carbide tools do not cover. I try to grind all the tools with the hss not getting to a light straw colour anywhere. Good hss has red hardness, so can be dull red hot and not have the hardness reduced. For small internal radius on a tool, I use either the desic diamond burs, or dress a mounted point to create that geometry. I find with the dremel stones or the desic diamond points, that a smear of cutting oil helps it cut a lot longer before clogging or going dull. The better the front or cutting surface finish on hss tools , the better the finish on the part, and the longer the tool will last as well. A mirror finished tool will last more than 3 times longer than a just ground tool from a 60 grit stone.