Manufactured from premium grade high speed steel. Killer Force Drills have a heavy duty 135 degree split point for self-centering and reducing thrust. Gold and black surface treated for use in stainless steel and other hard metal drilling. Drill set comes in a rust resistant, water and shatter proof BIT Cooler case. Set includes 29 drill bits from 1/16 to 1/2 in 1/64 increments.