Accupro T1620462B Spiral Point Tap 5/16-24 3 Flute Hss

Product Description

The ACCUPRO T1620462B is a spiral point tap designed for cutting 5/16-24 UNF internal threads in ferrous and non-ferrous materials, with a listed material application of stainless steel. It is manufactured from 3% vanadium high speed steel (HSS), which provides improved wear resistance and edge retention compared to standard M2 HSS. The plug chamfer distributes cutting load across the leading threads for use in through-hole applications. A black oxide finish reduces friction and provides light corrosion resistance during storage and service. Overall length is 2.7188 inches (69.06 mm) with a thread length of 22 mm and a shank diameter of 8.08 mm.

This tap is suited for machine tapping operations on CNC machining centers, drill presses, and tapping machines in job shop, production, and maintenance environments. It produces a Class 2B fit thread, which is the standard tolerance class for most inch-series fastener and general mechanical assembly applications. The right-hand thread direction and 3-flute spiral point geometry push chips forward ahead of the tap, making it effective in through-hole tapping where chip evacuation is critical. This tap does not support coolant-through delivery.

Key Features

• 5/16-24 UNF thread form for fine-pitch through-hole tapping
• 3-flute spiral point geometry pushes chips forward, reducing chip packing in through holes
• Plug chamfer distributes cutting load for smooth entry and reduced tap breakage
• 3% vanadium HSS construction for improved hardness and wear resistance over standard HSS
• Black oxide finish reduces friction and provides corrosion resistance during handling and storage
• Class 2B fit for standard general-purpose inch-series thread tolerance

Compatibility

Designed as a direct-use spiral point tap for 5/16-24 UNF through-hole tapping applications, compatible with standard 8.08 mm shank tool holders and tapping chucks used on manual and CNC machine tools.

Installation Notes

Installation is performed by a machinist or maintenance technician using a tapping chuck, rigid tap holder, or floating tap adapter rated for the shank diameter. Ensure the workpiece is securely fixtured and properly center-punched or pilot-drilled before tapping. Use a cutting fluid appropriate for the workpiece material, particularly when tapping stainless steel, to reduce heat buildup and extend tap life. Inspect the tap for chipping or wear before each use and replace if cutting edges are damaged to prevent tap breakage in the hole.