Osg 2931508 Spiral Flute Tap 3/8-16 Unc Ticn Vanadium Hss

Product Description

The OSG 2931508 is a spiral flute tap designed for cutting 3/8-16 UNC internal threads in a wide range of ferrous materials. Built from vanadium high-speed steel with a TiCN (titanium carbonitride) coating, it delivers extended wear resistance and reduced friction compared to uncoated HSS taps. The 45-degree helix angle pulls chips up and out of the hole during tapping, making it well suited for through-hole and blind-hole applications where chip evacuation is critical. The modified bottoming chamfer allows threading close to the bottom of a blind hole. Overall length is 3.156 inches with a shank diameter of 0.323 inches.

This tap is intended for use in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. It fits production and maintenance tapping operations in machine shop, fabrication, and industrial MRO environments. The H2 thread limit provides close dimensional control, making it appropriate for standard fit threaded assemblies. It is part of the OSG Series 290 and is sold individually. Machinists and toolroom professionals are the primary installers in CNC tapping, drill press, and hand-tapping setups.

Key Features

• 3/8-16 UNC right-hand thread form with H2 thread limit for controlled fit
• 45-degree spiral flute helix for efficient chip evacuation in blind and through holes
• TiCN coating increases surface hardness and reduces built-up edge on difficult materials
• Modified bottoming chamfer for threading close to the bottom of blind holes
• Vanadium HSS substrate provides toughness in interrupted cuts and harder workpieces
• 3 flutes balance chip room with core strength at this thread size

Compatibility

Rated for use in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel workpieces. Designed as an OEM-style replacement or direct tooling solution for 3/8-16 UNC tapping applications requiring an H2 thread limit and spiral flute geometry.

Installation Notes

Install in a rigid tap holder or floating tap chuck matched to the shank diameter before use. Ensure the workpiece is securely fixtured and that the tap is aligned axially with the drilled pilot hole to prevent tap breakage. Power down or de-energize any machine spindle before changing tooling. Use appropriate cutting fluid for the workpiece material, particularly when tapping stainless steel or hardened steel, to maximize tool life and thread quality.