drill bit Specification: (1.0-8.0) x 0.5 x10pcs+ (8.5-10.0s) x 0.5 x 5pcs drill bitSpecification: (1.0-8.0) x 0.5 x10pcs+(8.5-10.0) x 0.5 x 5pcsFinish: Black Finshed, Tin Coated, Bright, etc.Process: Roll Forged , Edge Ground or Fully GroundPacking: Metal Boxfor drillingin steel,cast steel,malleable iron,sintered metal, non-ferrous metal feel free to contact us for more detailed information