We at Cutting Tools Chicago aka General Cutting Tools along with Ingersoll Cutting Tools are going beyond the basics of finish milling to help you maximize the rigidity of your setup. Maximizing rididity will improve your end mill performance.
The HSK tool holder is designed to provide simultaneous fit on both the spindle face and the spindle taper.
At high speeds, centrifugal force causes the spindle to grow slightly. The face contact prevents the tool from moving up the bore. The hollow shank design is also susceptible to centrifugal force but is designed to grow with the spindle bore at very high speeds. I.D. clamping actually tightens its grip as spindle speed increases.
Supporting the cutting tool and holder in both the axial and radial planes creates a significantly more rigid connection between the tool and spindle.
Moreover, HSK end mill holders are available in a variety of clamping styles including shrink fit for solid carbide shanks; hydraulic for steel shanks, collet, and Weldon styles. Choose the most rigid and accurate assembly possible.
Other HSK advantages include lighter weight, lower deflection under load, extremely accurate repeatability, increased torque transfer capabilities, and significantly improved dynamic runout over 50-taper adaptations at high speeds.