Guhring 9039770254000 Spiral Flute Tap 1-8 Unc Cobalt Tin

Product Description

The GUHRING 9039770254000 is a spiral flute tap designed for bottoming thread applications in blind holes. It cuts a 1-8 UNC right-hand thread to a 2B class of fit and is manufactured from cobalt high-speed steel with a TiN (titanium nitride) coating for extended tool life in demanding materials. The fast flute style and 40-degree helix angle drive chips up and out of the hole efficiently, reducing the risk of chip packing in blind-hole work. Licensed machinists and tool-and-die tradespeople use this tap for production and maintenance threading in alloyed and unalloyed steel workpieces.

This tap is suited for blind-hole threading operations in alloyed steel and unalloyed steel. The bottoming chamfer allows threads to be cut to near the bottom of a blind hole, maximizing usable thread depth. With a 4-flute, right-hand spiral design and a shank diameter of 0.8 inches, it is intended for use in standard tap holders and CNC machining centers. It does not support coolant-through delivery. The Series 3977 designation identifies it within the GUHRING standard tapping product line.

Key Features

• Bottoming chamfer for maximum thread depth in blind holes
• Cobalt HSS construction for heat and wear resistance in steel applications
• TiN coating reduces friction and extends service life
• 40-degree helix angle with fast flute style for efficient chip evacuation
• Right-hand thread and right-hand flute, 4-flute configuration
• Thread limit H6 and H7 for precision tolerance control

Compatibility

Designed for blind-hole threading in alloyed steel and unalloyed steel. Produces a 1-8 UNC right-hand thread to a 2B class of fit with H6 and H7 thread limits.

Installation Notes

This tap is installed by a machinist or toolroom professional in a tap holder, floating tap head, or rigid CNC tapping setup. Always ensure the workpiece is securely fixtured and the machine spindle is stopped before changing tooling. Verify tap holder compatibility with the 0.8-inch shank and 0.6-inch square drive before use. Follow shop-floor speeds and feeds charts for cobalt taps in steel to avoid premature tool failure.