Osg 1294400 Extension Tap 8-32 Unc H3 Spiral Point Hss

Product Description

The OSG 1294400 is a spiral point plug extension tap designed for threading 8-32 UNC holes in materials requiring extended reach. Built from high speed steel with a bright uncoated finish, it features a 2-flute configuration and H3 thread limit for consistent fit tolerance in standard production and maintenance applications. The plug chamfer eases entry and distributes cutting forces gradually, making it well suited for through-hole tapping. At 6 inches overall length, the extended shank provides clearance for recessed bosses, deep fixtures, or workholding setups where a standard-length tap cannot reach. Licensed machinists and maintenance technicians are the primary installers.

This tap is rated for use in aluminum, carbon steel, cast iron, and hardened steel. The 2B class of fit produces a standard commercial thread tolerance suitable for the majority of fastener assemblies in general manufacturing, MRO, and machine shop environments. The right-hand flute and right-hand thread direction make it compatible with conventional CNC tapping cycles and hand-tap wrenches. The reduced shank and 0.755-inch neck length allow clearance past narrow bore entries before engaging the cutting zone.

Key Features

• Spiral point geometry pushes chips forward, reducing chip packing in through-hole applications
• H3 thread limit provides consistent 2B class of fit across aluminum, carbon steel, cast iron, and hardened steel
• 6-inch overall length delivers extended reach for recessed or deep-fixture tapping operations
• Reduced shank with 0.755-inch neck length clears narrow bore entries before thread engagement
• High speed steel construction balances toughness and wear resistance across a range of workpiece materials
• Bright uncoated finish allows direct visual inspection of cutting edges between uses

Compatibility

Designed as an OEM-style replacement or direct-application extension tap for 8-32 UNC through-hole tapping operations in standard tap wrenches, tapping heads, and CNC spindles accepting the specified shank diameter.

Installation Notes

Extension taps of this type are installed and operated by machinists or maintenance technicians following standard tapping procedures. Secure the workpiece fully before beginning; an unsecured part can seize the tap and cause breakage. Apply appropriate cutting fluid for the workpiece material to reduce heat and extend tool life. Ensure the tap is driven on-axis with the drilled hole to avoid thread distortion or tap fracture; misalignment is a leading cause of tap breakage on small-diameter threads.