Parlec C400TRK Retention Knob CAT40 5/8-11 Thread

Product Description

The PARLEC C400TRK is a Style C retention knob designed for CAT40 taper toolholders used in CNC machining centers. It threads into the drawbar of the spindle via a 5/8-11 thread and secures the toolholder during tool changes and cutting operations. With an overall length of 2.48 inches and a knob diameter of 0.588 inches, this retention knob meets the dimensional standards required for reliable pull-stud engagement in CAT40 spindle interfaces. The 45-degree angle radius profile is consistent with standard pull-stud geometry. Weighing 0.14 pounds, this is a precision machined component intended for installation by CNC machinists and toolroom technicians.

This retention knob is used in CAT40 toolholder assemblies on vertical and horizontal CNC machining centers equipped with automatic tool changers. It is suited for production and job-shop environments where consistent toolholder retention and repeatable positioning are required. The knob threads directly into the toolholder body and interfaces with the machine spindle drawbar mechanism. A pilot diameter of 0.635 inches and neck diameter of 0.404 inches allow proper seating and engagement within the toolholder bore.

Key Features

• CAT40 taper size for compatibility with standard CAT40 toolholders
• 5/8-11 thread size matches standard CAT40 drawbar thread specification
• 45-degree angle radius pull-stud profile for proper ATC gripper engagement
• 0.588 inches knob diameter and 0.635 inches pilot diameter for precise fitment
• Knob to flange length of 1.436 inches with 0.19 inches flange thickness
• Lightweight at 0.14 pounds for minimal spindle mass addition

Compatibility

Designed as a Style C OEM-style retention knob for CAT40 taper toolholders with a 5/8-11 drawbar thread. Confirm thread specification and pull-stud style with the machine spindle manufacturer before installation.

Installation Notes

Retention knobs should be installed by a qualified CNC machinist or toolroom technician. Power down and lock out the machine spindle before handling toolholder assemblies. Thread the retention knob into the toolholder to the manufacturer-specified engagement depth using the appropriate spanner wrench or retention knob installation tool. Do not use thread sealants or lubricants unless explicitly specified, as improper torque or contamination can affect toolholder seating and runout.