Osg 1295202 Extension Tap 5/16-18 Unc Spiral Point Hss

Product Description

The OSG 1295202 is a spiral point plug extension tap designed for cutting internal UNC threads in through-hole applications. Built from high-speed steel with an elektraLUBE finish, it produces 5/16-18 threads to a Class 3B fit tolerance, delivering tight, accurate thread geometry suited for production and maintenance work. The H3 thread limit provides a slightly oversize tap for use with standard threading operations where a controlled fit is required. At 6 inches overall length, the extended reach makes this tap useful for threading deep or recessed holes that standard-length taps cannot access. It is installed and operated by machinists, maintenance technicians, and tool-and-die professionals.

This tap is suited for through-hole threading operations in ferrous and non-ferrous materials where an extended reach is needed. The spiral point geometry pushes chips ahead of the cutting action, keeping the flutes clear and reducing the risk of chip packing. The reduced shank design and right-hand flute direction are consistent with standard tapping setups on manual machines, CNC machining centers, and drill presses. Typical applications include fabrication shops, MRO environments, and any setting requiring reliable 5/16-18 UNC thread production in locations beyond the reach of jobber-length taps.

Key Features

• Spiral point plug geometry pushes chips forward, ideal for through-hole threading
• High-speed steel construction provides durability across a range of workpiece materials
• elektraLUBE finish reduces friction and extends tool life during tapping operations
• H3 thread limit supports Class 3B fit for precise, close-tolerance thread production
• 6-inch overall length with reduced shank for extended reach into deep or recessed features
• Right-hand thread and flute direction compatible with standard tapping equipment

Compatibility

Designed for use in standard tapping chucks, floating tap holders, and rigid tapping setups sized for the OSG Series 917 reduced-shank extension tap configuration. Cuts 5/16-18 UNC internal threads to Class 3B fit.

Installation Notes

This tap should be installed by a qualified machinist or maintenance technician familiar with threading operations and proper speeds and feeds for high-speed steel tooling. Secure the tap in a properly sized tap holder or chuck before beginning the threading cycle, and verify workpiece fixturing before engaging the spindle. Use an appropriate cutting fluid or tapping compound compatible with the workpiece material to protect tool life. Never reverse a spiral point tap under power when chips have packed ahead of the cutting edges.