A set of 3 step drills / stepped cone cutters. Cuts a perfectly round hole in sheet metal. Hex shank prevents slipping in the drill chuck. New speed point tip penetrates faster and prevents walking. Double fluted design for speed and accuracy. Ideal for thin metals such as steel aluminium, copper, fibreglass and PVC etc... Drill sizes: Small Drill 4mm, 6mm, 8mm, 10mm and 12mm. Medium Drill 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm and 20mm. Small thin Drill 3mm, 4mm, 5mm, 6mm, 8mm, 9mm, 10mm and 12mm.