Pull Studs
The pull stud – also called a retention knob – is the single point of contact between your tool holder and the spindle’s draw-bar, so a worn thread or the wrong style stud is enough to cause incomplete draw-in, chatter, or a tool that won’t release cleanly. HS Spindles carries ISO30 pull studs built to DIN 69872 in the three styles most common on CNC machining centers: Colombo, HSD Biesse, and Elte. The three styles differ in head geometry and groove location, so a stud that threads in fine can still fail to engage the gripper or clamping mechanism correctly if it’s the wrong style for your spindle. Match the stud style to your machine builder’s spec sheet, not just the thread size, before ordering. Every stud is precision-threaded for a consistent draw-in fit against the spindle’s clamping unit.
