Guhring 9039840158750 Spiral Flute Tap 5/8-11 Unc

Product Description

The GUHRING 9039840158750 is a spiral flute tap designed for blind hole threading in alloyed and unalloyed steel. It cuts a 5/8-11 UNC right-hand thread with a modified bottoming chamfer, making it suitable for applications where threads must extend close to the bottom of a blind hole. The tap is manufactured from cobalt high-speed steel and carries a TiN (titanium nitride) coating to extend tool life under demanding cutting conditions. With a 40-degree helix angle and fast flute style, the design promotes efficient chip evacuation in ductile materials. The H11 thread limit specifies a slight oversize of 0.005 inches, accommodating post-plating or coating dimensional requirements. Overall length is 3.811 inches.

This tap is intended for use in machine tapping operations on alloyed and unalloyed steel workpieces. The modified bottoming chamfer allows threading in shallow blind holes where a standard or plug chamfer would leave too many unthreaded pitches at the bottom. It is used in CNC machining centers, turret lathes, and tapping machines in industrial, toolroom, and maintenance environments. Licensed machinists and tool and die professionals are the primary users. The 4-flute spiral configuration and fast flute style make it particularly effective in materials that produce continuous chips, where the helix lifts chips back out of the hole during the cut.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• Cobalt HSS construction provides heat and wear resistance in tough steel alloys
• TiN coating reduces friction and extends tool life
• 40-degree helix angle with fast flute style for efficient upward chip evacuation
• H11 thread limit with 0.005 inch oversize — suitable for parts that will be plated or coated after threading
• Right-hand flute and right-hand thread; compatible with standard tapping setups

Compatibility

Designed for machine tapping of 5/8-11 UNC blind holes in alloyed and unalloyed steel. Coolant-through is not supported; external coolant or cutting fluid application is required for optimal performance.

Installation Notes

Installation and use should be performed by qualified machinists following applicable shop safety procedures. Ensure the workpiece is securely fixtured and the tapping machine or CNC spindle is set to the correct RPM and feed rate for the workpiece material and tap size before engaging the tool. Apply an appropriate cutting fluid to the tap and hole before and during the operation; do not run this tap dry in steel. Inspect the tap for wear or chipping before each use and replace if damage is observed to prevent thread damage or tap breakage in the workpiece.