Scientific Cutting Tools QHC75-1/4 Boring Grooving Bar Holder

Product Description

The SCIENTIFIC CUTTING TOOLS QHC75-1/4 is a boring and grooving bar holder designed for use in CNC turning and boring applications. It features a 0.25 inch inner diameter and a 0.75 inch outer diameter, with an overall length of 3.25 inches and a head diameter of 0.87 inches. The holder is equipped with through-coolant capability via a 3/8-18 NPT coolant port, allowing direct coolant delivery to the cutting zone for improved chip evacuation and tool life. Four lock-down screws secure the boring or grooving bar firmly in place during operation. This holder is installed and used by machinists and CNC lathe operators working in precision machining environments.

This bar holder is suited for small-diameter boring and grooving operations on CNC lathes and turning centers. It is part of the Series QHC line, intended for applications requiring compact toolholding with through-coolant support. Typical use cases include internal diameter finishing, grooving, and threading operations where rigidity and coolant delivery at the cutting edge are critical to achieving tight tolerances.

Key Features

• 0.25 inch ID and 0.75 inch OD for small-bore toolholding applications
• 3.25 inch overall length with 0.87 inch head diameter
• Through-coolant design with 3/8-18 NPT coolant port for direct chip and heat management
• Four lock-down screws for positive, rigid bar retention
• Part of the Series QHC boring and grooving bar holder line

Compatibility

Designed as an OEM-style holder within the SCIENTIFIC CUTTING TOOLS Series QHC line, compatible with boring and grooving bars sized to a 0.25 inch shank diameter.

Installation Notes

Installation should be performed by a qualified machinist following the machine tool manufacturer guidelines. Ensure the machine spindle is fully stopped and the machine is in a safe, powered-down state before mounting or adjusting the holder. Torque all four lock-down screws evenly to secure the boring bar without inducing runout. Verify coolant line connection at the 3/8-18 NPT port is sealed before resuming coolant flow.