Super Primalloy "SST" bit goes father, faster Kimball Midwest's Super Primalloy "SST" Drill Bit is designed to penetrate stainless steel, aluminum, brass and other non-ferrous metals faster and more efficiently than conventional bits. Its heavy duty 135° split point eliminates center punching, preventing the common walking or wandering that can damage the piece. It is also 15% longer than maintenance length bits to provide full drilling depth and reach, and has a high helix flute design for superior chip flow and clearance.