Osg 1651506308 Spiral Point Tap 3/8-32 Unef Plug 3B

Product Description

The OSG 1651506308 is a spiral point plug tap designed for threading 3/8-32 UNEF internal threads in a wide range of metallic workpiece materials. Manufactured from powdered metal and coated with OSG V (VC-10) coating, it delivers enhanced wear resistance and heat dissipation compared to standard high-speed steel taps. The plug chamfer distributes cutting load across multiple leading threads for smooth thread entry. With a 3B class of fit and H3 thread limit, it produces close-tolerance threads suited to precision fastener applications. A licensed machinist or tooling technician typically runs this tap on CNC machining centers, drill presses, or tapping machines.

This tap is suited for production and job-shop threading operations across a broad material spectrum. OSG rates it for use in alloy steel, low-carbon steel, medium-carbon steel, high-carbon steel, hardened steel, cast iron, stainless steel, die steel, aluminum, and cast aluminum. The right-hand cut, 3-flute spiral point design pushes chips forward ahead of the tap, making it a strong choice for through-hole tapping applications where chip evacuation is critical.

Key Features

• 3/8-32 UNEF thread form with H3 thread limit and 3B class of fit for close-tolerance threading
• Powdered metal substrate with V (VC-10) coating for extended tool life in ferrous and non-ferrous materials
• 3-flute spiral point geometry pushes chips forward, optimizing through-hole tapping performance
• Plug chamfer (approximately 3-5 threads) for gradual thread engagement and reduced torque spike on entry
• Right-hand thread direction; no coolant-through feature required for standard tapping setups
• OSG Series 16515 EXOTAP VC-10 product line

Compatibility

Designed for threading 3/8-32 UNEF through-holes in alloy steel, low-carbon steel, medium-carbon steel, high-carbon steel, hardened steel, cast iron, stainless steel, die steel, aluminum, and cast aluminum workpieces. Fits standard tapping chucks and holders sized for a 0.381-inch shank diameter.

Installation Notes

This tap is installed and operated by machinists, tool-and-die makers, or CNC setup technicians. Secure the tap in a properly sized tapping chuck or floating tap holder to allow axial float and prevent thread distortion. Always apply appropriate cutting fluid or tapping compound for the workpiece material before starting the thread cycle. Inspect the tap for wear or chipping before each use and replace at the first sign of edge breakdown to avoid thread quality issues or tap breakage in the bore.