This is uncharted territory for me. Done similar stuff with wood using Brad point and Forstner bits but never with metal. Basically, I need a counterbore (CB) diameter of about 3/4" to a depth of about 3/8" in 1" thick
6061 aluminum. This is to create a recess for cap screw head and washer along with room to use a hex socket on the cap screw.Sourcing the correct CB and pilot seems easy enough except that MMC recommends HSS ($$) for ferrous and carbide tipped ($$$$) CB for non-ferrous metals. Surely, HSS should work for aluminum or am I missing something? Also, what would be the best drill speed to use in a case like this? I normally use wax lubricant for countersinking metal, is this good enough for counterboring? Finally, is it advisable to buy say a 1/2" aluminum blank and practice first or am I making a mountain out of a mole hill?