Parlec 5004TRK Retention Knob BT50 0.904 in Knob M24 Thread

Product Description

The PARLEC 5004TRK is a Style C retention knob designed for BT50 taper toolholders used in CNC machining centers. It threads into the drawbar mechanism of the spindle, securing the toolholder during high-speed cutting operations. Manufactured to close dimensional tolerances, the 5004TRK features a 0.904-inch knob diameter, a 3.34-inch overall length, and an M24 x 3.00 thread size. The 60-degree angle radius on the knob engages the drawbar gripper consistently, reducing the risk of pull-out under cutting loads. This knob is installed and torqued by CNC setup technicians and toolroom machinists.

The 5004TRK is intended for use with BT50 taper toolholders in horizontal and vertical machining centers that accept BT50 spindle interfaces. The BT50 taper is common in heavy-duty production machining environments where larger diameter tooling and higher torque capacity are required. The 0.983-inch pilot diameter and 1.77-inch knob-to-flange length are dimensioned to fit standard BT50 holder bodies. This knob is a direct replacement component used during toolholder rebuild or when an existing retention knob shows wear, damage, or thread degradation.

Key Features

• BT50 taper interface for compatibility with BT50 toolholder bodies
• M24 x 3.00 thread engages standard BT50 drawbar systems
• 60-degree angle radius for consistent drawbar gripper engagement
• 0.904-inch knob diameter and 0.983-inch pilot diameter for proper spindle seating
• Style C geometry with 0.667-inch neck diameter and 0.39-inch flange thickness
• 3.34-inch overall length fits standard BT50 holder pull-stud pockets

Compatibility

Designed as a direct-fit replacement retention knob for BT50 taper toolholders requiring an M24 x 3.00 thread and Style C knob geometry.

Installation Notes

Retention knobs are installed by CNC toolroom technicians using a retention knob torque wrench or spanner appropriate for the M24 thread. Always clean the threads on both the knob and toolholder bore before installation to prevent galling. Torque the knob to the toolholder manufacturer's specified value using a calibrated torque wrench - do not rely on impact tools. Inspect the knob and drawbar contact surfaces for wear during every toolholder service interval.