... twist drill bit set Material: HSS 4241, 4341, 9341, 6542 Finish: Black Finshed, Tin Coated, Bright, etc. twist drill bit setpecification: 1.5, ... 2, 3, 4, 5, 5.5, 6mmFinish: Black Finshed, Tin Coated, Bright, ... 3 edge ground,tin coatedH101-4 fully ground,brightH101-5 fully ground,black finishedH101-6 fully ground,tin coated