Accupro T2634583 Spiral Flute Tap 1/2-20 3 Flute Hss

Product Description

The ACCUPRO T2634583 is a spiral flute tap designed for threading 1/2-20 holes in steel workpieces. It features a modified bottoming chamfer, allowing threads to be cut close to the bottom of a blind hole. The tap is ground to a 3B class of fit with an H3 thread limit, making it suitable for standard tolerance threaded assemblies. Manufactured from 3% vanadium high speed steel, it offers improved wear resistance and edge retention compared to standard M2 HSS. The bright, uncoated finish is appropriate for general-purpose tapping in steel with proper cutting fluid. Overall length is 3.375 inches with a medium flute style and a 33-degree helix angle.

This tap is used in machine shop, maintenance, and production environments where 1/2-20 UNF threads are required in through or blind holes in steel. The spiral flute design helps evacuate chips upward out of the hole, making it especially effective in blind hole applications on CNC machining centers, drill presses, or manual tapping arms. It is intended for right-hand threads and right-hand flute direction. Typical users include machinists, tool and die makers, and maintenance technicians working with steel components requiring fine-thread fastener engagement.

Key Features

• 1/2-20 UNF thread size with modified bottoming chamfer for threading close to hole bottom
• 3% vanadium high speed steel construction for improved wear resistance over standard HSS
• H3 thread limit, 3B class of fit for standard tolerance threaded assemblies
• 33-degree helix angle with spiral flute design for efficient chip evacuation in blind holes
• Bright, uncoated finish suitable for use with cutting oils and general steel tapping
• Right-hand thread and right-hand flute direction

Compatibility

Designed for tapping 1/2-20 UNF threads in steel. The H3 thread limit and 3B class of fit are compatible with standard UNF threaded fasteners and inserts requiring a medium-tolerance fit.

Installation Notes

This tap should be installed in a tap holder or rigid tapping chuck appropriate for the shank diameter. Always apply a suitable cutting fluid when tapping steel to reduce heat buildup and extend tool life. Use at speeds recommended for high speed steel tooling in the workpiece material. Inspect the tap for chipping or wear before each use and do not force a worn or broken tap out of a hole without proper extraction tooling.