BB Step Drill 90 Degree for Steel CNC Precision Solid Carbide Drilling Tools Coated Screw Hole BB2055 Hole Diameter:2.1x5xD4x10x50 high thermal conductivity and good

high thermal conductivity and good thermal stability of metals

2 D4 12  50  4T 4  1

it makes your work easier

Tungsten steel makes the drill hardness higher

5 D10 100  200  3T 10R0

BB Step Drill 90 Degree for Steel CNC Precision Solid Carbide Drilling Tools Coated Screw Hole BB2055 Hole Diameter:2.1x5xD4x10x50 high thermal conductivity and goodOnce Formed Drilling + Chamfering The blade edge is sharp without burrs, easy chamfering Greatly improves work efficiency. Solid Carbide Bars High Hardness High Wear Resistance A specialized tool for high hardness and high speed cutting applications with higher wear resistance and strength Blade Nano Diamond Coating Aluminum Processing Strong Thermal Insulation Coating Nano Crystal Strong and Tough Base Film Enhance tool hardness and service life,