Irwin 10502854 step drill 5mm to 35mm 13 steps irwin 10502854 p this irwin step drill bit has been designed to enlarge a hole as the bit drills cleanly and accurately through the surface p p use this step drill bit for precision drilling of holes up to 35mm diameter in steel brass copper aluminium wood and plastic sheets p irwin 10502854 step drill 5mm to 35mm 13 steps in 2 to 3mm increments