Scientific Cutting Tools QHC75-5/16 Boring Grooving Bar Holder

Product Description

The SCIENTIFIC CUTTING TOOLS QHC75-5/16 is a boring and grooving bar holder designed to secure and position boring bars in CNC lathes and turning centers. It features a 5/16-inch inner diameter bore and a 3/4-inch outer diameter body, with an overall length of 3.25 inches and a head diameter of 0.87 inches. The holder includes a 3/8-18 NPT through-coolant port, allowing directed coolant delivery to the cutting zone for improved chip evacuation and tool life. Four lock-down screws provide firm, repeatable clamping of the boring bar during operation.

This holder is used in precision turning and boring operations on CNC lathes and manual turning centers. It is suited for internal grooving, profiling, and boring applications where secure tool retention and consistent coolant delivery are required. Machinists and toolroom technicians working in production or job-shop environments will find this holder fits into Series QHC tooling setups. The through-coolant design makes it well-suited for deep-bore or interrupted-cut applications where heat and chip buildup are concerns.

Key Features

• 5/16-inch ID bore and 3/4-inch OD body for use with matching boring bars
• 3.25-inch overall length for reach in standard turning applications
• 3/8-18 NPT through-coolant port for directed coolant delivery at the cutting zone
• Four lock-down screws for secure, repeatable bar clamping
• 0.87-inch head diameter sized for compact tooling setups
• Part of the Series QHC boring and grooving bar holder family

Compatibility

Designed as an OEM-style replacement or direct-fit tooling component for Series QHC boring and grooving bar holder setups using 5/16-inch ID boring bars.

Installation Notes

Installation is performed by qualified machinists or toolroom technicians. Power down and lock out the machine spindle before mounting or removing the holder from the turret. Tighten the four lock-down screws evenly to prevent bar deflection or runout. Verify coolant line connection at the 3/8-18 NPT port is leak-free before running the machine.