Accupro T4677565 Spiral Flute Tap 1/2-13 4 Flutes

Product Description

The ACCUPRO T4677565 is a spiral flute tap designed for cutting 1/2-13 UNC internal threads in ferrous and non-ferrous materials, with a primary application in cast iron. It features a modified bottoming chamfer, allowing threads to be cut close to the bottom of blind holes. The tap is manufactured from 3% vanadium high-speed steel and carries a nitride coating that improves surface hardness and extends tool life. With a right-hand, slow-helix flute geometry and four flutes, it is suited for use in CNC machining centers, lathes, and rigid tapping setups where consistent thread quality is required. Licensed machinists and tool-and-die professionals are the primary installers.

This tap is intended for tapping 1/2-13 UNC blind or through holes in cast iron and similar materials. The modified bottoming chamfer (typically 1 to 2 thread lead) makes it appropriate where thread engagement must start near the floor of a blind hole. The 2B class of fit produces standard commercial-tolerance threads suitable for most structural and mechanical fastening applications. It is designed for use in shops requiring a reliable, production-grade tap for medium-to-high volume runs.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• 4 right-hand spiral flutes with 15-degree helix angle for effective chip evacuation
• Vanadium high-speed steel (3% vanadium) construction for increased wear resistance
• Nitride coating adds surface hardness and reduces friction during cutting
• H5 thread limit maintains 2B class of fit tolerances
• Right-hand thread direction compatible with standard tapping equipment

Compatibility

Designed for cutting 1/2-13 UNC threads in cast iron per the material application specified by the manufacturer. Compatible with standard 1/2-13 tapping fixtures, CNC rigid tapping, and hand-tap holders that accept the listed shank diameter.

Installation Notes

Installation should be performed by qualified machinists following standard tapping procedures. Ensure the workpiece is securely fixtured and the spindle is properly aligned before beginning the tapping cycle. Apply appropriate cutting fluid for cast iron or the target material to extend tap life and improve thread finish. Inspect the tap for wear or chipping before each use, and do not force a worn tap into a blind hole, as breakage may result in costly extraction procedures.