Milwuakee 25 Piece HSS-G Co Red Cobalt Drill Piece Set includes sizes from 1mm to 13mm with a 3-flat shank from 5mm diameter for better grip which prevents chuck slippage. These are suitable for drilling high alloy content steels and metals with tensile strengths over 1000 N/mm like heat and acid proof steels and stainless steel. The metal drill bits are manufactured from solid extremely heat resistant cobalt-alloyed high speed steel produced according to DIN 338 with a polished finish.Features & Benefits- 3-Flat Shank for better grip which prevents chuck slippage- Suitable for drilling high alloy content steels and metals- 5&37; Cobalt content- Split point shaped cutting tip with 135 angle for improved centeringContents- 25 Piece Drill Bit Set In Sizes: 1, 1.5, 2, 2.5,3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5 and 13mm- Plastic Cassette Case