The BlueSpot 3 Pce Step Drill Set is specially designed for precision drilling of holes in aluminium, brass, copper, plastic, steel and wood. Manufactured from high steel for increased durability and cutting power. Titanium coated to reduce friction and heat. 2mm step increments. Set contains: 4-12mm in 2mm increments, five step drill, 4-22 in 2mm increments, ten step drill and 4-32mm in 2mm increments. Set is supplied in a robust metal case.