The problem and why it matters
Full compatibility with the machine spindle is the first requirement. Speed, torque, gauge length, repeatability and tool-change method are evaluated next.
HSK uses simultaneous taper and flange contact and is common in speed- and position-sensitive applications. Capto is a modular interface designed for torque transmission and rapid changeover.
Selection and design logic
No interface is universally best. Selection must follow the machine builder’s documentation and an analysis of the complete holder and tool assembly.
BT and SK belong to the 7:24 taper family; the spindle and drawbar standard determines which is applicable. Gauge length, flange geometry, retention knob and assembly balance must match the specific machine.
Implementation details and controllable errors
HSK’s taper-and-face contact and internal clamping suit many high-speed or repeatability-sensitive applications. Capto’s polygonal modular construction supports torque transfer and module changes, but only where the machine or a suitable adapter supports it.
Evaluation and conclusion
A decision table should include speed, torque, bending load, overhang, repeatability, change space and the plant’s existing holder inventory. A strong interface followed by several adapters may reduce real stiffness, so the shortest compatible chain is normally the better starting point.