Osg 1731008 Spiral Point Tap 3/8-16 Unc Ticn Hss

Product Description

The OSG 1731008 is a spiral point tap designed for cutting 3/8-16 UNC internal threads in a wide range of steel materials. It features a plug chamfer for through-hole threading applications and is manufactured from vanadium high speed steel (HSS-E) with a TiCN (titanium carbonitride) coating to extend tool life and reduce friction in harder workpiece materials. The tap carries an H3 thread limit and a 3B class of fit, making it suitable for standard-tolerance production threading. With 3 flutes and a right-hand thread direction, it pushes chips forward through the hole rather than packing them behind the tap. Licensed machinists, tool and die makers, and maintenance mechanics are the primary users.

This tap is suited for through-hole threading operations in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel. It fits standard hand-tap holders, CNC tapping heads, and drill press tapping attachments. The plug chamfer requires a through-hole or sufficient chip clearance beyond the threaded depth. At 2.937 inches overall length with a 0.381-inch shank diameter, it fits standard tap collets and holders sized for 3/8-inch shanks. It is a practical choice for job shops, maintenance facilities, and production lines running 3/8-16 UNC fastener holes.

Key Features

• 3/8-16 UNC thread form with H3 thread limit for standard 3B class of fit tolerances
• Vanadium high speed steel (HSS-E) construction for improved wear resistance over standard M2 HSS
• TiCN coating reduces friction and heat buildup, extending tool life in steel applications
• Plug chamfer (4-5 thread lead) optimized for through-hole threading
• 3-flute spiral point design pushes chips forward, keeping the flutes clear during cutting
• Right-hand thread direction, compatible with standard tapping equipment

Compatibility

Designed for use in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel workpieces. Compatible with standard tap holders, CNC rigid tapping spindles, and hand-tap wrenches sized for a 0.381-inch shank diameter.

Installation Notes

Always secure the workpiece fully before tapping and ensure the pilot hole is drilled to the correct tap drill size for 3/8-16 UNC threads. Secure the tap in a properly aligned holder to prevent tap breakage from misalignment. Apply an appropriate cutting fluid for the workpiece material, particularly when threading stainless or hardened steel. Tapping speeds should be set according to the workpiece material and machine type; consult the OSG Series 300 speed and feed recommendations for specific parameters.