Osg 2886305 Spiral Point Tap 1/2-20 Unf Tin Hss

Product Description

The OSG 2886305 is a spiral point tap designed for cutting 1/2-20 UNF right-hand internal threads in through-hole applications. Built from high-speed steel with a titanium nitride (TiN) coating, this tap delivers improved wear resistance and reduced friction compared to uncoated HSS tooling. It features a plug chamfer with 3 flutes and an H3 thread limit, making it well-suited for maintaining tight tolerances on 2B class of fit threaded connections. The overall length is 3.375 inches with a thread length of 0.941 inches and a shank diameter of 0.367 inches. Machinists and tool-and-die professionals use this tap in both manual and CNC tapping operations.

The 2886305 is rated for use in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel. Its spiral point geometry pushes chips forward ahead of the cutting zone, which makes it most effective in through-hole threading where chip evacuation is unobstructed. The plug chamfer provides a gradual lead-in that distributes cutting load across multiple threads, reducing the risk of tap breakage at entry. This tap is a practical choice for production environments where consistent thread quality across repeated cycles is required.

Key Features

• 1/2-20 UNF thread form, right-hand cut, 2B class of fit
• 3-flute spiral point geometry for forward chip ejection in through-holes
• Plug chamfer for gradual thread engagement and reduced entry load
• H3 thread limit for controlled tolerance on close-fit threaded assemblies
• TiN coating extends tool life and reduces galling in steel and aluminum
• High-speed steel construction provides toughness across a range of workpiece materials

Compatibility

Rated for use in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel workpieces. Intended for through-hole tapping applications requiring a 1/2-20 UNF 2B thread form.

Installation Notes

This tap should be installed by a qualified machinist in a tapping chuck, tapping head, or rigid CNC spindle that matches the 0.367-inch shank diameter. Always ensure the workpiece is securely fixtured and the tap is properly aligned to the drilled hole before engagement to prevent cross-threading or breakage. Use an appropriate cutting fluid or tapping compound for the workpiece material to maximize tool life and thread quality. Do not attempt to reverse or back the tap out under power without confirming the machine setup supports synchronized reversing.