Guhring 9039920222250 Spiral Point Tap 7/8-9 Unc Tin Hss

Product Description

The GUHRING 9039920222250 is a spiral point tap designed for through-hole threading in a wide range of ferrous materials. Manufactured from High-Speed Steel-E-PM (powder metallurgy HSS) and coated with titanium nitride (TiN), it delivers extended tool life and thermal resistance under production threading conditions. The tap is configured with 4 flutes, a plug chamfer, and a right-hand thread direction. It cuts a 7/8-9 UNC thread profile to a 2B class of fit with a thread limit of H6/H7. Overall length is 5.512 inches and thread length is 2.625 inches. Machinists, tool-and-die technicians, and maintenance mechanics use this tap in CNC machining centers, drill presses, and manual tapping operations.

This tap is suited for through-hole threading applications in steel, stainless steel, hardened steel, and chilled cast iron. The spiral point geometry pushes chips ahead of the tap and down through the hole, making it well matched to through-hole work where chip evacuation is straightforward. The plug chamfer provides a gradual thread lead-in, distributing cutting load across several threads. It is part of the GUHRING Series 3992 and is appropriate for both job-shop and production environments where consistent 7/8-9 UNC thread quality is required.

Key Features

• High-Speed Steel-E-PM construction for improved hardness and wear resistance compared to conventional HSS
• TiN coating reduces friction and extends tool life in ferrous materials
• Spiral point geometry pushes chips forward through the hole for clean through-hole threading
• Plug chamfer distributes cutting load gradually for smooth thread engagement
• 4-flute design provides strength and chip control at 7/8-9 thread size
• Right-hand cut, H6/H7 thread limit, 2B class of fit for standard UNC tolerances

Compatibility

Rated for threading in steel, stainless steel, hardened steel, and chilled cast iron. Designed as a through-hole threading tap for 7/8-9 UNC applications. Not rated for coolant-through use.

Installation Notes

Installation is performed by machinists or maintenance technicians using a tapping head, CNC rigid tapping cycle, or manual tap wrench. Power down and lock out any machine before changing tooling. Ensure the drilled hole is the correct tap-drill diameter for 7/8-9 UNC before tapping. Apply cutting fluid appropriate for the workpiece material to reduce tool wear and improve thread finish.