Parlec 4002TRK Retention Knob BT40 M16 X 2.00 Thread

Product Description

The PARLEC 4002TRK is a Style B retention knob designed for BT40 taper toolholders used in CNC machining centers. It threads into the drawbar mechanism to secure the toolholder inside the spindle during cutting operations. Key dimensions include a 0.588-inch knob diameter, a 2.36-inch overall length (OAL), and an M16 x 2.00 thread size. The 90-degree angle radius and 0.393-inch neck diameter are machined to BT40 interface standards. This knob is installed and removed by machinists and toolroom technicians during toolholder setup and changeover.

The 4002TRK is suited for BT40 spindle applications in vertical and horizontal machining centers running standard BT toolholder assemblies. It is a direct-fit component for shops using BT40 tooling in production or job-shop environments. The 0.669-inch pilot diameter and 1.376-inch knob-to-flange length position the knob correctly within the toolholder shank. This retention knob is appropriate for facilities where BT40 is the standard taper across the spindle inventory.

Key Features

• BT40 taper interface for compatibility with BT40 toolholder shanks
• M16 x 2.00 thread engages standard BT40 drawbar threads
• Style B configuration with 90-degree angle radius
• 0.588-inch knob diameter with 0.393-inch neck diameter for positive drawbar seating
• 0.669-inch pilot diameter ensures accurate centering in the spindle
• 2.36-inch OAL with 0.23-inch flange thickness for correct stack height

Compatibility

Designed as a replacement retention knob for BT40 taper toolholders requiring an M16 x 2.00 thread and Style B geometry.

Installation Notes

Retention knobs should be installed and torqued by a qualified machinist or toolroom technician following the toolholder manufacturer's assembly specifications. Power down and lock out the machining center spindle before servicing any toolholder assembly. Use the correct spanner or retention knob wrench to avoid damaging the knob or toolholder threads. Inspect threads on both the retention knob and toolholder for wear or damage before assembly.