Scientific Cutting Tools QHC75-3/16 Boring Grooving Bar Holder

Product Description

The SCIENTIFIC CUTTING TOOLS QHC75-3/16 is a boring and grooving bar holder designed for precision internal machining operations. It features a 3/16-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 is equipped with a 3/8-18 NPT through-coolant port, allowing coolant to be delivered directly to the cutting zone for improved chip evacuation and tool life. Four lock-down screws secure the boring bar firmly, reducing vibration and maintaining positional accuracy during operation. This holder is suited for CNC lathes and turning centers where internal grooving and boring operations require rigid, repeatable tooling setups.

This holder is used in precision turning and boring applications on CNC lathes and machining centers. It is well suited for shops running internal grooving or small-bore profiling operations where coolant delivery at the cutting edge is required. The through-coolant design makes it particularly effective in deep-bore applications and when machining difficult materials that generate heat or present chip-control challenges. Machinists and tooling technicians typically specify this holder when setting up QHC-series tooling systems.

Key Features

• 3/16-inch ID bore accommodates small-diameter boring and grooving bars
• 3/4-inch OD body for compact, rigid holder footprint
• 3.25-inch overall length suits standard turret and block tooling setups
• 3/8-18 NPT through-coolant port delivers coolant directly to the cutting zone
• Four lock-down screws provide secure clamping and minimize bar deflection
• 0.87-inch head diameter for close-clearance internal operations

Compatibility

Designed for use with QHC-series boring and grooving bars requiring a 3/16-inch shank diameter. Verify bar shank diameter and holder bore tolerances before installation.

Installation Notes

Installation is performed by qualified machinists or tooling technicians. Ensure the machine spindle is fully stopped and all energy is locked out before mounting or adjusting the holder in the turret or tool block. Torque all four lock-down screws evenly to secure the boring bar without inducing side load. Confirm through-coolant connections are properly sealed at the NPT fitting before pressurizing the coolant system.