Accupro T4677285 Spiral Flute Tap 8-32 Nitride Hss

Product Description

The ACCUPRO T4677285 is a spiral flute tap designed for threading 8-32 inch holes in production and maintenance machining operations. It features a modified bottoming chamfer, allowing threads to be cut close to the bottom of a blind hole. The tap is manufactured from 3% Vanadium High Speed Steel (HSS) and finished with a nitride coating that improves surface hardness and wear resistance. With a 15-degree helix angle and three right-hand flutes in a slow flute style, this tap efficiently evacuates chips while maintaining thread accuracy to an H5 thread limit. Overall length is 2.13 inches and the shank diameter is 4.27 millimeters.

This tap is suited for threading operations in cast iron and similarly machinable ferrous materials. The modified bottoming chamfer makes it practical for blind-hole applications where a standard or plug chamfer cannot reach full thread depth. It is used in machine shops, maintenance facilities, and production environments by machinists and maintenance technicians requiring precise internal threads in the 8-32 unified coarse pitch. The right-hand thread and right-hand flute orientation are standard for conventional CNC and manual tapping setups.

Key Features

• 8-32 thread size with H5 thread limit for controlled tolerance fit
• Modified bottoming chamfer allows threading close to the base of blind holes
• 3% Vanadium High Speed Steel construction for extended tool life in cast iron
• Nitride finish increases surface hardness and reduces friction during cutting
• 15-degree helix angle with slow spiral flute style promotes chip evacuation
• Right-hand thread and right-hand flute for standard tapping machine compatibility

Compatibility

Designed for use in cast iron and comparable ferrous materials. Suitable for standard tapping heads, CNC machining centers, and manual drill presses equipped for 8-32 tapping operations.

Installation Notes

This tap should be installed by a qualified machinist following standard toolroom or CNC setup procedures. Ensure the spindle is fully stopped and the workpiece is securely clamped before tool changes. Use appropriate tapping fluid or cutting oil for the workpiece material to extend tool life and maintain thread quality. Do not exceed the tap's rated capacity; overloading a spiral flute tap in a blind hole can result in breakage.