Osg 1736200 Pipe Tap 3/8-18 Npt 4 Flute Cobalt

Product Description

The OSG 1736200 is a standard NPT pipe tap designed for cutting 3/8-18 tapered pipe threads in a wide range of ferrous materials. Built from cobalt high-speed steel, it delivers improved heat and wear resistance compared to standard M2 HSS taps, making it a reliable choice for production and maintenance threading operations. The bright uncoated finish suits general-purpose applications where coating is not required. With 4 flutes and a regular hook geometry, this tap handles carbon steel, alloy steel, die steel, stainless steel, and hardened steel. Licensed plumbers, pipefitters, and machinists will find it at home on the bench or at the job site.

This tap is suited for threading pipe fittings, couplings, and manifold ports that require NPT tapered thread form. The 3/8-18 NPT designation means 3/8-inch nominal pipe size at 18 threads per inch. At 1-1/16 inches of thread length and an overall length of approximately 2.56 inches, it fits standard tap wrenches and machine holders for both hand tapping and low-speed machine tapping. Typical applications include HVAC refrigerant line connections, plumbing system fittings, hydraulic manifolds, and instrumentation ports.

Key Features

• Cobalt HSS construction for elevated heat resistance in difficult-to-machine materials
• 3/8-18 NPT thread form for standard tapered pipe thread connections
• 4-flute regular hook geometry for controlled chip formation in through and blind applications
• 1-1/16 inch thread length provides full engagement for NPT taper
• Bright uncoated finish compatible with most cutting fluids and tapping compounds
• Series 328 OSG standard pipe tap designation for direct reorder and replacement

Compatibility

Designed for threading carbon steel, alloy steel, die steel, stainless steel, and hardened steel workpieces requiring 3/8-18 NPT tapered pipe threads. Fits standard tap wrench drives with a 0.531-inch square drive size and a 0.700-inch shank diameter.

Installation Notes

Pipe taps should be installed by qualified machinists, pipefitters, or plumbers using a properly sized tap wrench or low-speed machine spindle. Always apply an appropriate cutting fluid or tapping compound for the material being threaded, and back the tap off periodically to break and clear chips. Secure the workpiece firmly before tapping to prevent movement and thread misalignment. Follow applicable codes such as ASME B1.20.1 for NPT thread dimensions and tolerances when thread quality is critical to system integrity.