Guhring 9039910048260 Sti Tap 10-32 Unf Cobalt Tin Plug

Product Description

The GUHRING 9039910048260 is a spiral point STI tap designed for through-hole threading in 10-32 UNF Screw Thread Insert applications. Built from cobalt high-speed steel and finished with a Titanium Nitride (TiN) coating, this tap delivers extended tool life and reduced friction during cutting. It features a plug chamfer, 3 flutes, and a 3B class of fit, making it suitable for precise threaded insert preparation. Overall length is 2.5 inches with a thread length of 0.5 inches and a shank diameter of 0.255 inches. It belongs to GUHRING Series 3991 and is sold as a single unit.

This tap is intended for machinists, maintenance technicians, and tool-and-die professionals performing STI thread repair or preparation. It is used when installing Heli-Coil or similar wire thread inserts that require an oversized tapped hole in the 10-32 UNF profile. Compatible material applications include aluminum, stainless steel, and steel. The spiral point geometry pushes chips forward, making it best suited for through-hole operations rather than blind-hole work.

Key Features

• STI UNF thread standard — sized for wire thread insert installation in 10-32 applications
• Cobalt construction for improved heat and wear resistance versus standard HSS
• Titanium Nitride (TiN) coating reduces friction and extends cutting life
• Plug chamfer provides a balance of lead-in guidance and thread depth capacity
• 3-flute spiral point design pushes chips ahead of the tap for clean through-hole threading
• 3B class of fit ensures precise tolerance control for threaded insert applications

Compatibility

Designed for through-hole STI threading in aluminum, stainless steel, and steel workpieces requiring a 10-32 UNF Screw Thread Insert profile with a 3B class of fit.

Installation Notes

This tap should be installed and operated by qualified machinists or maintenance technicians familiar with STI tapping procedures. Always secure the workpiece and use appropriate tapping fluid or cutting oil matched to the workpiece material before beginning the threading operation. Ensure the tap is properly aligned with the pilot hole to avoid tap breakage, particularly in harder materials such as stainless steel. Power down all equipment and follow applicable shop safety protocols before changing or inspecting tooling.