Osg 2931601 Spiral Flute Tap 3/8-16 Unc 3 Flutes Hss

Product Description

The OSG 2931601 is a spiral flute tap designed for cutting internal 3/8-16 UNC threads in a wide range of ferrous materials. Built from vanadium high-speed steel with a steam oxide coating, it delivers improved lubricity and corrosion resistance during tapping operations. The modified bottoming chamfer allows threading closer to the bottom of blind holes than a standard plug tap. With a 45-degree helix angle and right-hand spiral flute geometry, the tap pulls chips up and out of the hole, reducing packing in deeper applications. Licensed machinists and tool-and-die professionals will find this tap well suited to production and maintenance work alike.

This tap is rated for use in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. The 3B class of fit produces a standard tolerance internal thread suitable for general fastener assembly. The H3 thread limit provides controlled oversize for plated or coated mating fasteners. Series 290 from OSG covers spiral flute taps intended for through-hole and blind-hole applications where chip evacuation is a priority. It is commonly used in job shops, production machining cells, and maintenance-and-repair operations.

Key Features

• 3/8-16 UNC thread form with H3 thread limit for controlled tolerance
• Modified bottoming chamfer for threading close to blind-hole floors
• 45-degree right-hand spiral flute pulls chips up and out of the hole
• Vanadium high-speed steel construction for wear resistance in ferrous materials
• Steam oxide coating improves lubricity and reduces galling
• 3B class of fit for standard general-purpose thread assemblies

Compatibility

Rated for use in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. Not rated for coolant-through applications.

Installation Notes

Install and operate using a tapping head, CNC machine, or hand tap wrench appropriate for the shank diameter. Power down all machine tools and secure the workpiece before tool changes. Apply a cutting fluid compatible with the workpiece material to extend tool life and improve thread finish. Follow shop safety practices and applicable OSHA machine-guarding requirements when operating tapping equipment.