Accupro T2670163 Spiral Point Tap 4-40 2 Flute Hss

Product Description

The ACCUPRO T2670163 is a spiral point tap designed for cutting 4-40 unified fine threads in through-hole applications. It features a plug chamfer style, 2 flutes, and is manufactured from 3% vanadium high speed steel (HSS) with a bright finish. The spiral point geometry pushes chips forward ahead of the tap, keeping the flutes clear during through-hole operations. With an overall length of 1.87 inches (47.6 mm) and a thread length of 11 mm, this tap is sized for small-diameter work in machine shop and production environments. Installation is typically performed by machinists and CNC operators using a tapping head or machine spindle.

This tap is suited for threading aluminum and similar non-ferrous materials in light to medium production environments. The H3 thread limit provides a controlled oversize tolerance that accommodates coatings and fits standard 4-40 fastener systems. Its compact shank diameter of 3.58 mm makes it compatible with standard collets and tap chucks used in benchtop drill presses, CNC machining centers, and manual tapping fixtures. The right-hand thread direction is consistent with standard 4-40 screw systems.

Key Features

• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• 3% vanadium high speed steel construction for wear resistance in aluminum and non-ferrous materials
• H3 thread limit for controlled tolerance fits on 4-40 threaded assemblies
• Plug chamfer for general-purpose through-hole starting
• Bright finish — no coating that would alter thread geometry
• Right-hand thread direction, compatible with standard 4-40 fastener systems

Compatibility

Designed as an OEM-style replacement or standard tooling tap for 4-40 unified fine thread through-hole applications in aluminum and similar non-ferrous workpieces.

Installation Notes

This tap should be installed and operated by qualified machinists familiar with small-diameter tapping procedures. Always secure the workpiece firmly before tapping and use appropriate cutting fluid for the workpiece material to prevent tap breakage. Ensure spindle speed and feed rate are appropriate for the 4-40 thread size and material to avoid overloading the tap. Do not reverse a broken tap without proper extraction tools.