Metalworking & Multipurpose Drill Bits / Gun Drill BitsStep Sizes:3-12mm: 9 steps (3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 12mm)3-14mm: 12 steps (3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm)4-12mm: 9 steps (4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm)4-20mm: 9 steps (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm)4-22mm: 10 steps (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm)4-26mm: 12 steps (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm)5-21mm: 9 steps (5mm,7mm, 9mm, 11mm, 13mm, 15mm, 17mm, 19mm, 21mm)5-27mm: 12 steps (5mm,7mm, 9mm, 11mm, 13mm, 15mm, 17mm, 19mm, 21mm, 23mm, 25mm, 27mm)6-24mm: 11 steps (6mm, 8mm, 10mm, 12mm, 13mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm)