Guhring 9039970063500 Spiral Point Tap 1/4-28 Unf Tin

Product Description

The GUHRING 9039970063500 is a spiral point tap designed for through-hole threading operations in demanding materials including stainless steel. Built from powdered metal and finished with a titanium nitride (TiN) coating, this tap delivers improved wear resistance and tool life compared to standard high-speed steel alternatives. It cuts a 1/4-28 UNF right-hand thread to a 3B class of fit with an H3 thread limit, making it well suited for precision fastener applications where fit tolerance matters. The 3-flute, plug chamfer design pushes chips ahead of the cut, keeping flutes clear during through-hole passes. Overall length is 2.5 inches with a shank diameter of 0.255 inches.

This tap is sized for 1/4-28 UNF threaded holes in through-hole configurations. The plug chamfer provides a gradual lead-in of several threads, making it appropriate for production tapping in CNC machining centers, drill presses, and manual tapping setups. The TiN coating and powdered metal substrate are particularly effective when threading stainless steel, where heat generation and tool wear are primary concerns. Series 3997 from GUHRING is a standard production tap line suited to both job shop and volume manufacturing environments.

Key Features

• Powdered metal construction for increased toughness and wear resistance over standard HSS
• TiN coating reduces friction and extends tool life in abrasive and work-hardening materials
• Plug chamfer (spiral point) pushes chips forward, ideal for through-hole threading
• 1/4-28 UNF thread form, H3 thread limit, 3B class of fit for precise thread tolerance control
• Right-hand cut, 3-flute design compatible with standard tapping chucks and tap holders
• No coolant-through requirement — suitable for external flood or mist coolant delivery

Compatibility

Designed for through-hole threading in stainless steel and similar work-hardening materials. Fits standard 1/4-inch tap holders and tapping chucks accepting a 0.255-inch shank diameter. Part of GUHRING Series 3997.

Installation Notes

Installation of taps should be performed by a qualified machinist following standard shop safety practices. Ensure the workpiece is securely fixtured and the spindle is properly aligned before engaging the tap. Use appropriate cutting fluid or coolant for the material being threaded to prevent galling, especially in stainless steel. Never reverse a spiral point tap under load without disengaging the drive to avoid flute damage or tap breakage.