Micro 100 QTH-207 Boring Grooving Bar Holder

Product Description

The MICRO 100 QTH-207 is a boring and grooving bar holder engineered for precision machining applications. Part of the QTH series, this tool holder accepts a 0.3125-inch inside diameter boring bar and features a 0.75-inch outside diameter shank for secure tool post or turret mounting. The overall length is 2.8 inches, and the head diameter measures 0.875 inches. A coolant-through design delivers cutting fluid directly to the tool tip, improving chip evacuation and extending tool life during internal grooving and boring operations. Machinists and CNC lathe operators working on tight-tolerance bore work will find this holder suited to demanding production and job-shop environments.

The QTH-207 is intended for use on CNC lathes and turning centers where internal boring and grooving operations require a rigid, repeatable bar holder. Its coolant-through capability makes it particularly well suited to interrupted cuts, deep bore applications, and materials that generate significant heat at the cutting edge. The compact 2.8-inch overall length keeps overhang minimal, contributing to reduced vibration and improved surface finish in the finished bore.

Key Features

• Coolant-through design directs fluid to the cutting zone for improved chip flushing and heat control
• 0.3125-inch inside diameter accepts standard QTH-series boring and grooving bars
• 0.75-inch outside diameter shank for consistent, rigid turret or tool post seating
• 0.875-inch head diameter provides a stable clamping surface
• Compact 2.8-inch overall length minimizes overhang and reduces chatter risk
• Part of the QTH series for compatibility with other MICRO 100 QTH tooling components

Compatibility

Designed for use with MICRO 100 QTH-series boring and grooving bars requiring a 0.3125-inch bore holder with a 0.75-inch outside diameter shank.

Installation Notes

Installation should be performed by a qualified machinist following the machine tool manufacturer's guidelines for turret or tool post mounting. Ensure the machine spindle is fully stopped and the machine is in a safe, locked-out state before mounting or removing the holder. Verify that all clamping fasteners are torqued to the machine tool manufacturer's specified values before beginning a cut. Connect the coolant-through port to the machine's coolant supply line before operation to take full advantage of the holder's cooling capability.