Accupro T1640425 Spiral Point Tap 1/4-28 3 Flutes Plug

Product Description

The ACCUPRO T1640425 is a spiral point tap designed for cutting right-hand internal threads in through-hole applications. Built from HSS-E Vanadium high speed steel with an oxide finish, this tap delivers added wear resistance and lubricity during cutting operations. It is configured with a plug chamfer and 3 flutes, making it well-suited for machine tapping in production environments. The overall length is 2.5 inches, with a thread length of 0.748 inches and a shank diameter of 0.255 inches. Licensed machinists, tool-and-die makers, and maintenance technicians working in metal fabrication or industrial maintenance typically install and operate this tap.

This tap cuts 1/4-28 UNF threads, a fine-pitch thread standard commonly found in precision assemblies, thin-walled components, and fastener applications where increased thread engagement is required. The H5 thread limit keeps finished threads within close tolerance, making it appropriate for controlled-fit fastener bores in steel, aluminum, and similar machinable metals. The spiral point design pushes chips forward ahead of the tap, which reduces clogging in through-hole work and allows for higher feed rates in automated or semi-automated tapping setups.

Key Features

• HSS-E Vanadium construction for improved heat resistance and cutting edge retention
• Oxide finish reduces friction and provides moderate corrosion resistance during storage and use
• Plug chamfer with 3 flutes supports efficient chip evacuation in through-hole tapping
• H5 thread limit ensures close-tolerance thread production for precision fitment
• Right-hand thread direction compatible with standard CNC and manual tapping equipment
• No coolant-through feature — suitable for flood coolant or cutting fluid applied externally

Compatibility

Designed for through-hole tapping of 1/4-28 UNF threads in machinable metals using standard tap holders, tapping heads, and CNC machine tool spindles that accept straight-shank taps with a 0.255-inch shank diameter.

Installation Notes

This tap should be installed and operated by qualified machinists or maintenance personnel familiar with tapping feeds, speeds, and cutting fluid requirements for the workpiece material. Always secure the workpiece and confirm the tap holder is properly aligned before beginning the tapping cycle to avoid tap breakage or thread damage. Apply an appropriate cutting fluid externally before and during the tapping operation to extend tool life and improve thread quality. Follow your facility and machine manufacturer guidelines for tapping speeds when using this tap in CNC or turret-style tapping equipment.