Osg 1312901 Pipe Tap 3/8-18 Nptf 4 Flute Hss Oxide

Product Description

The OSG 1312901 is a standard pipe tap designed to cut 3/8-18 NPTF threads in metal workpieces. Built from high-speed steel with an oxide finish, this tap delivers the interference-fit thread form required for pressure-tight pipe connections. The 4-flute regular hook geometry provides controlled chip evacuation in through and blind hole applications. Overall length is 2.56 inches, thread length is 1-1/16 inches, and the shank diameter measures 0.700 inches. It is used by plumbers, pipefitters, HVAC technicians, and machinists wherever dryseal pipe threads are required.

This tap is rated for use in carbon steel, cast iron, and aluminum. It is suited for threading pipe ports, fittings, manifolds, and housings in residential and commercial mechanical systems. The NPTF thread profile creates a pressure-tight seal on assembly without relying solely on thread sealant, making it the correct choice for hydraulic, pneumatic, and fluid-conveying connections. The Series 118 designation identifies the OSG product family for this pipe tap geometry.

Key Features

• 3/8-18 NPTF thread form produces dryseal pipe threads for pressure-tight connections
• High-speed steel construction provides wear resistance across carbon steel, cast iron, and aluminum
• Oxide finish reduces friction and provides light corrosion protection during storage and use
• 4-flute regular hook geometry supports efficient chip removal in standard tapping operations
• Square size of 0.531 inches fits standard tap wrenches and machine holders
• Thread length of 1-1/16 inches provides adequate engagement depth for typical pipe port applications

Compatibility

Designed for threading 3/8-18 NPTF pipe ports in workpieces of carbon steel, cast iron, and aluminum. Suitable for hand tapping and machine tapping setups where a standard pipe tap driver or tap wrench with matching square drive is used.

Installation Notes

NPTF pipe taps are typically installed by machinists, pipefitters, or HVAC technicians using a tap wrench or CNC tapping attachment. Ensure the pilot hole is drilled to the correct tap drill size for 3/8-18 NPTF before threading. Apply a suitable cutting fluid to reduce heat and extend tool life, particularly in cast iron and steel. Secure the workpiece firmly and maintain axial alignment throughout the tapping operation to prevent tap breakage.