Drill drilling high-strength steel and ultra-high-strength steel, how to choose?

Drilling high strength steel, the choice of high-performance high-speed steel twist drill or carbide drill. Drilling ultra-high-strength steel, the general should be used carbide drill diameter greater than 16mm hole, recommended use indexable drill with.cutting disc

High-speed steel twist, the choice of the group of three sharp edge shaped drill drill or repair ground. In order to improve the rigidity of the drill should be appropriately increase Zuanxin thickness, to reduce the amount of overhang. Helix angle should also be smaller, and is generally 17 ° to 30 °.cutting wheel

Choice carbide drill, you can increase the angle, to improve chip removal and general of for 2kr = 140 ° to 150 °. Should be reduced in order to reduce the axial force to the chisel, drill diameter is generally 0.1do (do). The drill feed the anterior horn gf = 0 ° to feed posterior horn af = 6 ° to 12 °. Indexable drill with a blade should be used in coated blade and non-blade coating. Recommend use of coated inserts: YB01, YB02, YB03; non-coated blades: YC10, YC30, YC40, YD20, 798,813, etc..