Sizes 1/16″ to 1/2″ by 64ths;Bit remains sharp up to 4 times longer than conventional drill bits;Speedy tip design eliminates need for pilot holes and prevents bit from walking on curved surfaces;Mechanics length speedy tip bit makes them less prone to breakage;Patented cobalt-tungsten hi-molly alloy; 3/16” – 1/2″; 1/16” – 11/64”