Features: 1.With 3 Flutes & 90 degrees point angle. 2.Made of high qulaity HSS material,hardness and durable. 3.Suitable for use in the work-piece which the hardness is under 25 degrees. 4.Cutting quickly & easily in wood,aluminum sheet,thin iron plate,the insulating board or PVC board. 5.It's very sharp and durable,you can use it for a long time. Descriptions: 1.This is a 3 Flute HSS Hard Metals Countersink Drill Bit Set. 2.Compact size and lightweight,convenient to carry and operate. 3.Suitable for cutting wood,aluminum sheet,thin iron plate,the insulating board or PVC board. Specifications: Material: High Speed Steel Color:Silver Size: Head diameter x the shank diameter x total length 6.3MM: 6.3MM x 5MM x 37MM 8.3MM: 8.3MM x 6MM x 40MM 10.4MM: 10.4MM x 6MM x 39MM 12.4MM: 12.4MM x 10MM x 46MM 16.5MM: 16.5MM x 10MM x 47MM 20.5MM: 20.5MM x 10MM x 47MM Quantity: 6pcs Package information: Package Size:150x110x33mm/5.85x4.29x1.29in Package weight:134g/4.69oz General Box Package Package included: 1 x Countersink Drill Bit Set Noted: 1.There could be some slight differences in the color tone of the pictures and the actual item. 2.Please allow 1-2mm differs due to manual measurement, thanks.