Even if you want to drill a hole into sheet metal, thin material, for automotive or aeronautical purposes, for a rivet hole or simply to double the life of your current stub length drill bit, the ultimate effectiveness is now offered to you on a silver plate. SST+ 135 deg. DOUBLE-END STUB DRILL The state of the art cobalt blend provides these drill bits an uncomparable lifespan that would make any black oxide competitiors blush..