Accupro T2634422B Spiral Flute Tap 1/4-28 3 Flutes 2B

Product Description

The ACCUPRO T2634422B is a spiral flute tap designed to cut internal 1/4-28 UNF threads in a wide range of ferrous and non-ferrous materials. Built from 3% vanadium high-speed steel, it delivers increased wear resistance and edge retention compared to standard M2 HSS taps. The modified bottoming chamfer allows threading closer to the bottom of a blind hole, making it well suited for close-tolerance work where thread depth is critical. With a right-hand flute direction and a 33-degree helix angle, chips are pulled up and out of the hole efficiently, reducing the risk of chip packing. Overall length is 2.5 inches, with a 12 mm thread length. This tap is used by machinists, toolroom technicians, and maintenance mechanics on production and repair work.

This tap is appropriate for general machining, maintenance, and repair operations requiring 1/4-28 UNF internal threads. The modified bottoming chamfer suits blind-hole applications in small to medium components across industries including aerospace, automotive, and general fabrication. It is sized for use in standard drill press, CNC, or hand-tapping operations where a 3-flute spiral geometry is preferred for chip evacuation in short to medium chip-producing materials.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• 3% vanadium high-speed steel construction for improved wear resistance and tool life
• 33-degree helix angle promotes upward chip evacuation in blind holes
• 2B class of fit for standard commercial tolerance internal threads
• Bright/uncoated finish suitable for general-purpose tapping applications
• Right-hand thread and right-hand flute direction for conventional tapping setups

Compatibility

Designed as an OEM-style replacement or direct-use tap for any application requiring a 1/4-28 UNF, 2B class of fit, modified bottoming spiral flute tap in standard toolholder collets or tap chucks accepting a 6.48 mm shank diameter.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tap wrench, drill press, or CNC tapping head. Always ensure the correct tap drill size for 1/4-28 UNF is used prior to tapping, and apply appropriate cutting fluid for the workpiece material. Secure the workpiece firmly before beginning the tapping operation. Do not force the tap if resistance increases suddenly, as breakage in blind holes is difficult to recover from.