Scientific Cutting Tools QHC75-3/8 Boring Grooving Bar Holder

Product Description

The SCIENTIFIC CUTTING TOOLS QHC75-3/8 is a boring and grooving bar holder designed for use with modular boring bar systems in precision machining applications. The holder accepts a 3/8 inch inner diameter boring bar and features a 3/4 inch outer diameter body with an overall length of 3.25 inches and a head diameter of 0.87 inches. A 3/8-18 NPT through-coolant port delivers cutting fluid directly to the cutting zone, supporting tool life and chip evacuation during internal grooving and boring operations. Four lock-down screws secure the bar firmly in position.

This bar holder is intended for use on CNC lathes, turning centers, and manual lathes equipped with compatible modular tooling systems. It suits production and job-shop environments where internal grooving, boring, or profiling operations require a rigid, coolant-fed tool interface. The Series QHC designation identifies it within a family of quick-change holders designed for repeatable setup in high-volume or precision turning work. Machinists and toolroom technicians are the primary installers of this style of toolholder.

Key Features

• 3/8 inch ID bore accepts standard 3/8 inch boring and grooving bars
• 3/4 inch OD body for compact, rigid bar support
• 3/8-18 NPT through-coolant port for directed coolant delivery
• Four lock-down screws provide secure, chatter-resistant bar clamping
• 3.25 inch overall length suits typical turning center tool stations
• 0.87 inch head diameter for close-clearance internal work

Compatibility

Designed as an OEM-style replacement or direct addition for modular boring and grooving bar tooling systems accepting 3/8 inch diameter boring bars in the Series QHC holder family.

Installation Notes

Installation is performed by qualified machinists or toolroom technicians. Ensure the machine spindle is fully stopped and the tool turret or holder block is de-energized before inserting or removing the bar holder. Tighten all four lock-down screws evenly to the toolholder manufacturer's recommended procedure to prevent bar deflection or pullout during cutting. Verify the through-coolant port connection is leak-free before commencing the machining cycle.