3Or4" I.D. Hsk-63A Guhring Shrink Fit Holder With Conventional Or Mql Coolant, 100Mm Gage Length Hsk-A To Iso12164-1 / Din 69893-1 | Balanced To G2.5 / 25,000 Rpm | Includes 4 Or 6 M6 Balancing Screws | For Tool Shank Tolerance H6 | To Din 69882-8 | Includes Setting Screw, Series No. 4977 Or 4904 | For Conventional Cooling Order Coolant Supply Set, Series 4949 Separately | Suitable For Tools With Internal Coolant. A Gripping Principle: When Shrink Fitting Tools Into Shrink Fit Chucks, The Decisive Factors For Ensuring The Safe Clamping Of The Tool In The Tool Holder Are Solely The Heating And Cooling Of The Tool Holder. The Heating Process Expands The Shrink Fit Chuck Enabling A Tool To Be Inserted Or Withdrawn Respectively. During The Cooling Process It Contracts Again And Clamps The Inserted Tool With Maximum Clamping Force. Series No. 4736, Order Code 919.0630. Made In Germany, Guhring Part #9047369190630