HSK Holders Toolholders with HSK taper per DIN STD 69893 are used on modern CNC milling machines of the latest generation. For coolant through tools, HSK toolholders can be equipped with a coolant tube (KSR) that ducts the coolant directly to the cutting tool, thereby prohibiting coolant to enter and soil the HSK taper area. REGO-FIX® Q+ HSK toolholders are balanced by design to G 2.5 @ balanced for high speeds in excess of 25,000 rpm and higher. For highest precision and best results, the total system counts. For that reason, all REGO-FIX® components (collets, clamping nuts and toolholders) are carefully matched to fit together. This guarantees the lowest T.I.R. and maximum balancing. For best manufacturing results and longest tool life, please use REGO-FIX® toolholders together with REGO-FIX® collets and clamping nuts only. For highest clamping force, as required for tapping with GB collets or ET1 collets, we recommend REGO-FIX® friction bearing nuts. REGO-FIX® end mill holders and universal shell mill/face mill holders are manufactured to the same exacting standards as all other REGO-FIX® products.