Osg 1311100 Npt Pipe Tap 1/8-27 4 Flute High Speed Steel

Product Description

The OSG 1311100 is a standard NPT pipe tap designed to cut 1/8-27 tapered pipe threads in metallic workpieces, with a primary material application in aluminum. It belongs to OSG Series 108AL and features a 4-flute geometry with a high hook angle, promoting efficient chip evacuation during tapping operations. The tap is manufactured from high-speed steel and carries a bright, uncoated finish — suited for use with cutting fluids where coating is not required. Overall length measures 2.126 inches, with a 0.75-inch thread length and a shank diameter of 0.4375 inches. This tool is installed by machinists, pipefitters, and plumbing or HVAC technicians threading pipe fittings or port connections.

The 1311100 is used when creating NPT-compliant tapered internal pipe threads in aluminum components such as manifolds, housings, valve bodies, and fluid system ports. The 1/8-27 NPT thread size is common in low-pressure instrumentation lines, gas pilot ports, hydraulic fittings, and HVAC refrigerant line access ports. This tap is appropriate for both shop and field applications where a clean, properly tapered pipe thread seat is required for leak-free fitting connections. It is compatible with standard tapping chucks and manual tap handles that accept a 0.4375-inch round shank with a 0.3280-inch square drive.

Key Features

• 1/8-27 NPT thread profile for tapered pipe thread applications
• 4-flute design with high hook angle for improved chip flow in aluminum
• High-speed steel construction provides durability across general-purpose tapping
• Bright, uncoated finish compatible with standard cutting oils and tapping fluids
• 0.75-inch thread length suits typical pipe fitting wall thickness
• Series 108AL geometry optimized for aluminum material application

Compatibility

Designed for cutting standard NPT tapered pipe threads per the 1/8-27 specification, primarily in aluminum workpieces. Fits standard tap handles and tapping chucks accepting a 0.4375-inch shank diameter.

Installation Notes

This tap is intended for use by qualified machinists, pipefitters, or mechanical technicians. Secure the workpiece fully before tapping and use an appropriate cutting fluid or tapping compound rated for aluminum to extend tool life and produce clean thread forms. Apply consistent, even torque and back off periodically to break chips when tapping by hand. Follow applicable shop safety practices and, for plumbing or gas line applications, verify thread engagement and sealant requirements per IFGC or IPC guidelines before pressurizing the system.