Accupro T2634463 Spiral Flute Tap 5/16-24 3 Flute Hss

Product Description

The ACCUPRO T2634463 is a spiral flute tap designed for cutting 5/16-24 UNF internal threads in a wide range of metals and engineered materials. It features a modified bottoming chamfer for threading close to the bottom of blind holes, 3 right-hand flutes with a 33-degree helix angle, and is manufactured from 3% vanadium high speed steel for improved wear resistance and edge retention. The H3 thread limit holds a 3B class of fit, making it suitable for standard-tolerance fastener applications. The bright, uncoated finish is appropriate for use with cutting oils and general-purpose threading operations. Overall length is 2.7188 inches.

This tap is used in machine shop, maintenance, and production environments where 5/16-24 blind-hole threading is required. The spiral flute design ejects chips up and out of the hole, making it well suited for threading ductile materials such as aluminum, mild steel, and similar alloys. It is commonly run in CNC machining centers, drill presses, and tapping heads. The modified bottoming chamfer allows threads to be cut closer to the bottom of a blind hole than a standard plug tap, which is useful when thread engagement depth is constrained by part geometry.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• 33-degree helix angle promotes upward chip ejection in ductile materials
• 3% vanadium high speed steel construction for extended tool life
• H3 thread limit for 3B class of fit tolerances
• Right-hand flute, right-hand thread geometry
• Bright, uncoated finish compatible with standard cutting fluids

Compatibility

Designed for use in standard tapping chucks, CNC rigid tapping setups, and drill press tapping attachments that accept the 8.08 mm shank diameter. Suitable for 5/16-24 UNF threading applications requiring a 3B class of fit.

Installation Notes

This tap should be installed by a machinist or tooling technician in a properly aligned tapping chuck or holder. Ensure the workpiece is securely fixtured and the tap is started square to the hole to prevent tap breakage or thread distortion. Use an appropriate cutting fluid for the workpiece material. When threading blind holes, set depth stops carefully to avoid bottoming the tap under power.