1. High quality elastic steel material with long use time.
2. Type: A AD AD/B
3. Shank of the Arbors：BT30, BT40, BT50, DIN69871.A30, DIN69871.A40, DIN69871.A50, CT40, CT50. DIN2080
4. The precision little than 0.005mm with balance 8000rpm. Higher precision also can be made by your demand. (G6.3/12000rpm, G2.5/20000rpm)
5. Holder hardness: HRC 52-55