Techniks 21005-90C CAT50 Retention Knob 1-8 Thread

Product Description

The TECHNIKS 21005-90C is a CAT50 retention knob engineered for use in CNC machining centers that use the CAT50 taper toolholder standard. It features a 1-8 inch thread size, a 90-degree angle radius, and a knob diameter of 0.906 inches with an overall length of 3.346 inches. The through-coolant design allows coolant flow directly through the knob, supporting high-pressure coolant delivery to the cutting zone. This component is installed by CNC machinists and toolroom technicians as part of the toolholder retention system in the machine spindle drawbar assembly.

This retention knob is suited for CAT50 toolholders used in vertical and horizontal machining centers operating on 1-8 threaded drawbar systems. The 90-degree angle radius seat helps ensure consistent clamping force and proper toolholder pull-up against the spindle taper. Through-coolant capability makes it appropriate for applications requiring directed coolant flow, including deep-hole drilling, reaming, and high-speed milling operations where heat management at the cutting tool is critical.

Key Features

• CAT50 taper size for compatibility with CAT50 toolholder shanks
• 1-8 inch thread matches standard CAT50 drawbar thread specification
• 90-degree angle radius for consistent seating and clamping force distribution
• Through-coolant design supports high-pressure coolant delivery to the cutting zone
• 0.906 inch knob diameter and 3.346 inch overall length fit standard CAT50 retention systems

Compatibility

Designed for use with CAT50 taper toolholders on CNC machining centers equipped with a 1-8 inch threaded drawbar and through-coolant spindle capability.

Installation Notes

Installation is performed by a CNC machinist or toolroom technician. The drawbar must be fully released and the spindle must be powered down before removing or installing retention knobs. Use the correct thread engagement depth and torque the knob per the machine tool manufacturer specifications - do not overtighten, as this can distort the toolholder taper or damage the drawbar thread. Inspect the knob seating surface and thread condition before each installation.