Osg 1295600 Spiral Point Extension Tap 5/8-11 Hss

Product Description

The OSG 1295600 is a spiral point extension tap designed for threading 5/8-11 UNC holes in production and maintenance machining environments. Built from high-speed steel with a bright, uncoated finish, this right-hand tap features 3 flutes and a plug chamfer that pushes chips forward ahead of the cutting action, making it well suited for through-hole threading applications. The H3 thread limit provides a controlled fit for 3B class threads. At 6 inches overall length, the extended reach allows operators to thread deeper into workpieces or clearance-restricted fixtures that a standard-length tap cannot access.

This tap is used in through-hole threading operations across a range of materials including aluminum, carbon steel, cast iron, and hardened steel. The extension length is particularly useful in fixture setups, deep bores, or applications where the tap drive must clear an obstruction before reaching the hole. It is typically run in CNC machining centers, drill presses, or manual tapping equipment. The reduced shank and 0.36-inch square drive allow it to seat in standard tap holders and chucks sized for this shank diameter.

Key Features

• Spiral point design pushes chips forward for clean through-hole threading
• H3 thread limit produces 3B class of fit for standard tolerance threaded fastener assemblies
• 6-inch overall length provides extended reach into deep or clearance-restricted workpieces
• High-speed steel construction handles aluminum, carbon steel, cast iron, and hardened steel
• Reduced shank with 0.36-inch square drive fits standard tap holders for this range
• Bright, uncoated finish - suitable for use with cutting fluids appropriate to the workpiece material

Compatibility

Designed for 5/8-11 UNC through-hole threading operations in aluminum, carbon steel, cast iron, and hardened steel. Compatible with standard tap holders and drive chucks accepting a 0.48-inch shank diameter and 0.36-inch square drive.

Installation Notes

This tap should be installed and operated by a qualified machinist or toolroom technician. Ensure the tap holder is properly aligned with the hole axis before engaging to prevent tap breakage and thread damage. Apply a suitable cutting fluid for the workpiece material throughout the tapping operation. Never reverse a spiral point tap under load without first confirming chip clearance in the hole.