Main Features：

1, The material: Alloyed case hardened steel, black-finished and precisely grinded 

2, The precision: 0.005mm 

3, The hardness: 52-58HRC 

4, Surface: black, sand-blasting

5, Taper tolerance: AT3

6, Dynamic balancing can be made G6.3/12000rpm, G2.5/25000rpm