Techniks 21134-C Retention Knob BT30 M12 Thread

Product Description

The TECHNIKS 21134-C is a retention knob designed for BT30 taper toolholders used in CNC machining centers. It threads into the drawbar mechanism inside the spindle, securing the toolholder during operation and allowing it to be released by the tool change system. The 21134-C features an M12 thread size, an 11 mm knob diameter, a 60-degree angle radius, and an overall length of 1.6929 inches. Through-coolant capability is included, supporting spindle-delivered coolant applications. This component is installed by CNC machinists and toolroom technicians as part of routine toolholder setup and maintenance.

This retention knob is intended for use with BT30 taper toolholders in vertical and horizontal machining centers equipped with BT30 spindles. It is suited for shops running high-speed or precision work where consistent drawbar engagement is critical. The through-coolant feature makes it compatible with toolholders configured for internal coolant delivery, reducing the need for external coolant nozzle positioning on close-tolerance work.

Key Features

• BT30 taper size for direct fitment in BT30 spindle systems
• M12 thread size for standard BT30 drawbar compatibility
• 11 mm knob diameter for proper automatic tool changer engagement
• 60-degree angle radius for reliable drawbar pull-stud geometry
• Through-coolant capable for internal coolant delivery applications
• 1.6929 inch overall length for correct seating depth

Compatibility

Designed as an OEM-style replacement or spare retention knob for BT30 taper toolholders requiring an M12 thread pull stud.

Installation Notes

Retention knobs are installed by CNC machinists or toolroom personnel during toolholder assembly. Power down and lock out the machining center before handling spindle components or toolholders. Use the appropriate spanner or retention knob wrench to achieve proper seating without overtightening. Inspect the drawbar and toolholder taper for wear or contamination before installing a new retention knob.