Global Cnc Industries 8612B .312 Tool Holder Bushing Type B

Product Description

The GLOBAL CNC INDUSTRIES 8612B .312 is a Type B rotary tool holder bushing designed for use in drill press, milling, and CNC machining setups where precise bore location and tool guidance are required. It features a 0.3125-inch inside diameter and a 1.2500-inch outside diameter, with a head thickness of 0.265 inches. The 2.125-inch length under the head provides substantial engagement depth for stable tool support. This bushing is installed by machinists and toolroom technicians as a replaceable liner in jig plates and tool holder bodies to maintain accurate, repeatable positioning of rotating tooling.

Type B bushings are commonly used in production jig and fixture applications where a fixed-type liner is needed without a locking collar. This part fits standard jig plate bores sized for 1.250-inch OD bushings and is suited for light-to-medium duty drilling, reaming, and boring operations in both manual and CNC-assisted machining environments. It is appropriate for job shop and production floor use where consistent hole location tolerances must be maintained across repeated operations.

Key Features

• Type B fixed-liner bushing for jig plate and tool holder applications
• Inside diameter of 0.3125 inches (5/16 inch) for compatible drill and reamer shanks
• Outside diameter of 1.2500 inches (1-1/4 inch) for standard jig plate bore fitment
• Head thickness of 0.265 inches provides a positive stop and prevents axial migration
• Length under head of 2.125 inches (2-1/8 inch) for deep engagement and tool guidance stability
• Minimum order quantity of 1 unit - suitable for single-piece replacement or toolroom stocking

Compatibility

Designed as an OEM-style replacement or new-installation bushing for jig plates and tool holder bodies requiring a Type B fixed liner with a 1.2500-inch outside diameter bore and a 0.3125-inch inside diameter.

Installation Notes

Installation is performed by qualified machinists or toolroom personnel. Press-fit the bushing into the jig plate bore using an arbor press, ensuring the bore and bushing OD are clean and free of burrs before pressing. Do not use impact tools to drive the bushing, as this can damage the bore geometry or distort the bushing. Verify inside diameter clearance with the intended tool shank before placing the jig plate into service.