Osg 1251308 Spiral Flute Pipe Tap 1/4-18 Npt Ticn Hss

Product Description

The OSG 1251308 is a spiral flute pipe tap designed for cutting internal NPT threads in a variety of metal workpieces. Built from high-speed steel and coated with titanium carbonitride (TiCN), this tap delivers improved wear resistance and extended tool life compared to uncoated alternatives. The bottoming chamfer allows threading closer to the bottom of a blind hole, while the 15-degree helix angle and 4-flute spiral design promote efficient chip evacuation during the tapping operation. At 2-7/16 inches overall length with a 9/16-inch shank, it fits standard tap holders used in machine or hand tapping setups. Machinists and pipefitters rely on this tap for precision NPT thread production in production and maintenance environments.

This tap is suited for tapping 1/4-18 NPT threads in materials including aluminum, carbon steel, cast iron, and hardened steel. The TiCN coating provides a harder surface than TiN, making it a practical choice for higher-hardness workpieces or higher-volume tapping runs. The bottoming chamfer is particularly useful in applications where thread engagement near the base of a blind hole is required, such as in hydraulic fittings, pipe fittings, and pneumatic manifolds. The 3/8-inch projection provides appropriate reach for standard pipe tap applications.

Key Features

• 1/4-18 NPT thread size for standard pipe thread applications
• TiCN coating for increased surface hardness and wear resistance over uncoated HSS
• Bottoming chamfer for threading close to the bottom of blind holes
• 15-degree helix angle with 4 flutes for effective chip removal
• Compatible with aluminum, carbon steel, cast iron, and hardened steel
• Right-hand flute direction for standard tapping operations

Compatibility

Designed for tapping 1/4-18 NPT threads in aluminum, carbon steel, cast iron, and hardened steel workpieces. Part of the OSG S125 series.

Installation Notes

This tap should be installed by a qualified machinist using a tap wrench or CNC/manual machine with an appropriate tap holder sized for the 9/16-inch shank diameter. Always secure the workpiece firmly and apply cutting fluid appropriate for the workpiece material before beginning the tapping operation. Ensure the machine spindle or tap wrench is properly aligned with the pre-drilled pilot hole to prevent tap breakage. Power down or disengage the machine before changing taps or clearing chips.