Osg 1315100 Pipe Tap 1/8-27 Npt 5 Flutes High Speed Steel

Product Description

The OSG 1315100 is a 1/8-27 NPT interrupted thread pipe tap manufactured from high-speed steel with a bright finish. It is designed for cutting tapered pipe threads in a range of materials including aluminum, carbon steel, cast iron, and hardened steel. The interrupted thread geometry reduces cutting friction and helps clear chips during the tapping operation, making it well suited for deeper or blind-thread applications. With 5 flutes, a modified bottoming chamfer, and a regular hook angle, this tap is built for production and maintenance environments where accurate NPT threads are required. A licensed machinist or skilled tradesperson typically installs and operates this tool.

This tap is used in applications requiring NPT pipe thread entry points in metal components, fixtures, and assemblies. The 1/8-27 NPT size is common in plumbing, pneumatic, and hydraulic fittings across residential and light commercial work. The modified bottoming chamfer allows threading closer to the bottom of a drilled hole compared to a standard taper chamfer, making it useful when thread engagement depth is limited. The OSG Series 108G designation identifies this as a current catalog production tap intended for tapping operations on the materials listed above.

Key Features

• Interrupted thread design reduces cutting friction and improves chip evacuation
• Modified bottoming chamfer allows threading closer to restricted-depth holes
• 5-flute geometry provides multiple cutting edges for smoother thread form
• High-speed steel construction handles aluminum, carbon steel, cast iron, and hardened steel
• Bright finish with no coating for straightforward inspection and reuse
• 1/8-27 NPT thread standard for tapered pipe thread applications

Compatibility

Designed for cutting 1/8-27 NPT tapered pipe threads in aluminum, carbon steel, cast iron, and hardened steel workpieces. Fits standard tap holders and machine spindles accepting a 0.4375-inch shank diameter with a 0.3280-inch square drive.

Installation Notes

This tap is operated by a machinist or experienced tradesperson using a tap wrench, tapping head, or CNC machine tool spindle. Ensure the workpiece is securely fixtured and the pilot hole diameter matches the recommended tap drill size for 1/8-27 NPT before beginning. Use appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. Never force a tap against resistance — back off periodically to break and clear chips.