Osg 2957600 Spiral Flute Tap 3/8-16 Unc 2 Flutes H5

Product Description

The OSG 2957600 is a spiral flute tap designed for cutting 3/8-16 UNC internal threads in through-hole and modified bottoming applications. Built from vanadium high-speed steel with a bright uncoated finish, this tap runs a 50-degree helix angle that promotes efficient chip evacuation up and out of the flute. It carries a 2B class of fit and an H5 thread limit, making it well-suited for standard tolerance threaded fastener applications. The 2-flute geometry reduces cutting resistance, while the modified bottoming chamfer allows threading close to the bottom of a blind hole without a dedicated bottoming tap. Machinists and toolroom techs working in production or maintenance environments install this tap by hand or under machine power in standard tap holders.

This tap is rated for aluminum as its primary material application, where its high-speed steel construction and spiral flute design handle the gummy chip characteristics of aluminum alloys effectively. The modified bottoming chamfer suits jobs where thread depth must reach near the base of a blind hole. With a 0.5-inch thread length and an overall length of 2.938 inches, it fits standard tap holders and CNC tapping chucks used in vertical machining centers and drill presses alike. It is sold as a single unit with no minimum order quantity above one piece.

Key Features

• 3/8-16 UNC thread form, 2B class of fit, H5 thread limit for standard tolerance compliance
• 50-degree right-hand spiral flute promotes upward chip evacuation, reducing recutting
• Modified bottoming chamfer allows threading close to the bottom of blind holes
• Vanadium high-speed steel construction provides wear resistance in aluminum and similar non-ferrous materials
• Bright uncoated finish suits aluminum applications where coating adhesion or lubrication may affect performance
• 2-flute geometry reduces torque requirements and cutting resistance

Compatibility

Designed as an OEM-style cutting tool replacement for spiral flute tapping operations in 3/8-16 UNC thread applications. Primary material application is aluminum as specified by the manufacturer.

Installation Notes

This tap should be installed in a tap holder or floating tapping chuck that matches the shank diameter and square drive dimensions. Power down all spindle motion and secure the workpiece firmly before tool changes. Always apply a cutting fluid appropriate for the workpiece material to extend tool life and maintain thread quality. Follow shop safety protocols and ANSI B94.9 standards where applicable for tapping tool use.