i have an assortment of drill bill sets from home depot and a few other placed like that. mostly the small ones are broken, the rest i use for wood, and they make nice round holes.
i tried to drill through conduit and saw lots of smoke so i guess these bits are not very good.
i do have a set of bits i bought at a tool show. no name, but on the bits it is stamped HSS. they cut right through the conduit.
what does HSS mean and what does case hardened mean if anything.
thank you all in advance.