Technical specs:
1- Hardness: 46~48 HRC
2- RPM: 1050r/min (BOSCH type)
3- Life: dia.4~8, 80~90 holes; dia.10~up, 100~150 holes
4- Steel material: 40Cr
5- Carbide tips material: YG8
6- Surface: sand blasting or steel color
7- Package: PVC bag or plastic tube