Carbide tip geometry for speed and durability. For use on standard drills. Includes: 3/16", 1/8", 2-5/32", 2-3/16", 1/4", 5/16", 3/8" and 1/2". Organized in a durable case. Master Mechanic 10 Piece Rotary masonry drill bit set Carbide tip geometry for speed and durability For use on standard drills Includes: 3/16", 1/8