Osg 1311200 Npt Pipe Tap 1/4-18 4 Flute Hss

Product Description

The OSG 1311200 is a standard NPT pipe tap designed to cut 1/4-18 tapered pipe threads in aluminum and similar non-ferrous materials. Built from high-speed steel (HSS) with a bright, uncoated finish, this 4-flute tap produces clean, accurate threads for pressure-tight pipe connections. It measures 2.437 inches overall length with a 1-1/16-inch thread length and a 0.5625-inch shank diameter. The high-hook flute geometry promotes efficient chip evacuation in softer materials, reducing the risk of chip packing and tap breakage. Plumbers, pipefitters, HVAC technicians, and machinists use this tap when threading new fittings, manifold blocks, or port connections that require a standard NPT taper profile.

This tap is suited for threading aluminum workpieces in residential, commercial, and light industrial applications. Common install scenarios include tapping ports in aluminum manifolds, valve bodies, pump housings, and pipe fittings that will accept 1/4-18 NPT threaded connections. The NPT taper profile produces the slight interference fit necessary for leak-free joints when used with appropriate thread sealant or PTFE tape. The Series 108AL designation indicates formulation and geometry optimized for aluminum cutting.

Key Features

• 1/4-18 NPT taper thread profile for standard pipe connections
• High-speed steel construction provides toughness and wear resistance
• 4-flute, high-hook geometry promotes chip evacuation in aluminum
• Bright, uncoated finish — no coating buildup to affect thread tolerance
• 0.5625-inch shank diameter fits standard tap wrench or machine collet
• Series 108AL — geometry optimized for aluminum material applications

Compatibility

Designed for cutting 1/4-18 NPT tapered pipe threads in aluminum workpieces. Series 108AL geometry is specified for aluminum material applications.

Installation Notes

This tap is installed by a machinist, pipefitter, or plumber using a tap wrench or tapping head sized for the 0.5625-inch shank. Always drill the correct NPT tap drill size before tapping and ensure the workpiece is securely fixtured. Apply a suitable cutting fluid formulated for aluminum to extend tap life and improve thread finish. Inspect threads with an NPT ring gauge after tapping to verify proper fit before assembling pipe connections.