Guhring 9039900035050 Spiral Point Sti Tap 6-32 Unc

Product Description

The GUHRING 9039900035050 is a spiral point STI tap designed for through-hole threading operations in demanding shop environments. Built from cobalt high-speed steel with a titanium nitride (TiN) coating, this tap delivers extended tool life when cutting stainless steel and alloy steels. It is sized for 6-32 UNC threads, runs 3 flutes with a plug chamfer, and meets a 3B class of fit. Overall length is 2.38 inches with a thread length of 0.335 inches. The spiral point geometry pushes chips forward through the hole, making it well-suited for through-hole applications where chip evacuation is critical. Machinists, toolroom technicians, and maintenance professionals rely on this tap for precision thread repair and production threading.

This tap is intended for through-hole threading in stainless steel and steel workpieces. The STI (Screw Thread Insert) designation means the tap cuts an oversized thread profile to accept helical wire inserts such as Heli-Coil-style thread inserts, restoring or upgrading thread strength in stripped or understrength bores. It fits standard tap wrenches and CNC tapping heads configured for the 0.194-inch shank diameter. Typical applications include thread repair on machinery housings, fabrication of tapped holes in stainless steel components, and production threading in medium to high-volume operations where a durable coated tap reduces tool change frequency.

Key Features

• Cobalt HSS construction resists heat and wear when tapping stainless steel and alloy steels
• Titanium nitride (TiN) coating reduces friction and extends tool life between regrinds
• Spiral point geometry pushes chips ahead of the tap, keeping through-holes clear during cutting
• STI thread profile cuts oversized threads sized to accept standard wire thread inserts
• Plug chamfer provides a gradual lead-in for balanced cutting action in through-hole applications
• 3B class of fit meets standard tolerance requirements for general-purpose threaded assemblies

Compatibility

Designed as an OEM-style STI tap for through-hole threading operations requiring 6-32 UNC thread inserts in stainless steel and steel materials; part of GUHRING Series 3990.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician using a properly aligned tap wrench, tapping arm, or CNC tapping head. Ensure the workpiece is securely fixtured and the spindle or wrench is aligned square to the bore before beginning. Use a cutting fluid or tapping compound appropriate for the workpiece material, particularly when tapping stainless steel, to reduce heat buildup and prevent galling. Do not exceed the rated torque capacity of the tap for the thread size, and back off periodically to break chips if tapping manually.