Techniks 21003 Retention Knob CAT40 45 Degree Angle Radius

Product Description

The TECHNIKS 21003 is a CAT40 retention knob designed to secure toolholders in CAT40 spindle tapers on CNC machining centers. The knob features a 45-degree angle radius and a 0.74-inch knob diameter, providing a reliable pull-stud interface between the toolholder and the machine spindle drawbar. Weighing just 0.05 pounds, this compact component plays a critical role in maintaining accurate tool seating, reducing runout, and ensuring consistent clamping force during high-speed cutting operations. It is installed by machinists and CNC setup technicians as part of routine toolholder assembly or replacement.

This retention knob is suited for use in CAT40 toolholding systems on vertical and horizontal CNC machining centers across job shops, production facilities, and toolrooms. It is a direct-fit pull-stud style component used when assembling CAT40 endmill holders, shell mill arbors, collet chucks, and similar toolholders before loading into the spindle. The 45-degree angle radius is the standard configuration for most CAT40 drawbar systems. Through-coolant is not supported with this knob.

Key Features

• CAT40 taper size for compatibility with standard CAT40 spindle systems
• 45-degree angle radius matches the drawbar engagement profile on most CAT40 machining centers
• 0.74-inch knob diameter for proper fitment in CAT40 toolholder retention knob bores
• No through-coolant configuration keeps the design straightforward for dry or flood coolant setups
• Lightweight at 0.05 pounds for easy handling during toolholder assembly

Compatibility

Designed as an OEM-style replacement or spare retention knob for CAT40 toolholders requiring a 45-degree angle radius pull stud configuration. Verify drawbar thread specification on your specific machine before installation.

Installation Notes

Retention knobs are installed by machinists or CNC setup technicians using the appropriate spanner or retention knob wrench. Always power down and lock out the machine spindle before removing or installing toolholders and retention knobs. Torque the retention knob into the toolholder per the toolholder manufacturer specifications before loading into the spindle. Inspect the knob and toolholder threads for wear or damage before each assembly.