High-precision balanced HSK63AHSK100A-SLN20/25/32/40/50 Side-set shanks U-drill shanksHSK Side set shanks U drill shanks The tool handle is designed with double sided constraints, closely fitting with both sides of the spindle,reducing the imbalance of the tool system, reducing vibration, and effectively enhancing the rigidity of the tool handle Closely fitting with both sides of the spindle HSK63A HSK100A Side Lock End Mill Holder Material 20CrMnTi Hardness 58 62HRC Accuracy 0. 003mm Advantage Full size Support Non standard Model No.