Parlec 4005TRK Retention Knob CAT40 5/8-11 Thread

Product Description

The PARLEC 4005TRK is a Style C retention knob designed for CAT40 toolholders used in CNC machining centers. It secures the toolholder to the machine spindle drawbar with a 5/8-11 threaded shank, providing the clamping force required for reliable tool engagement during milling, drilling, and boring operations. The knob measures 2.3 inches overall length with a knob diameter of 0.588 inches and a pilot diameter of 0.635 inches. It is installed and torqued by CNC machinists and toolroom technicians as part of routine toolholder assembly or replacement.

This retention knob fits CAT40 taper toolholders and is suited for use in horizontal and vertical machining centers with a standard CAT40 spindle interface. The 45-degree angle radius geometry seats consistently against the drawbar. With a knob-to-flange length of 1.268 inches, neck diameter of 0.393 inches, and flange thickness of 0.13 inches, it meets common dimensional requirements for CAT40 toolholder assemblies in production and job shop environments. No through-coolant feature is present on this part.

Key Features

• CAT40 taper size for compatibility with CAT40 spindle drawbar systems
• 5/8-11 threaded shank for secure drawbar engagement
• 45-degree angle radius for consistent seating geometry
• Style C configuration with 0.635 inches pilot diameter for accurate toolholder registration
• Compact 2.3 inches overall length suits standard CAT40 toolholder stack heights
• No through-coolant passage - straightforward solid knob construction

Compatibility

Designed as an OEM-style replacement or assembly component for CAT40 taper toolholders requiring a 5/8-11 thread retention knob with Style C geometry.

Installation Notes

Retention knobs are installed by CNC machinists or toolroom personnel using a retention knob wrench and torque wrench calibrated to the toolholder manufacturer specifications. Always de-energize and lock out the machining center spindle before removing or installing toolholders. Inspect the drawbar threads and toolholder bore for damage or contamination before threading in the knob. Do not exceed the toolholder manufacturer recommended torque value for this thread size.