Accupro T2640165 Spiral Point Tap 4-40 3 Flutes Plug

Product Description

The ACCUPRO T2640165 is a spiral point tap designed for cutting right-hand internal threads in a 4-40 unified fine thread form. With 3 flutes and a plug chamfer, it pushes chips forward ahead of the cutting zone, making it well suited for through-hole tapping operations. The tap is manufactured from vanadium high speed steel (3% vanadium HSS), which provides improved wear resistance and edge retention compared to standard M2 HSS. The bright finish leaves the tool in an uncoated state, appropriate for use with cutting fluids on a range of steel workpiece materials. The H5 thread limit governs the tolerance class of the finished thread, producing a fit suitable for standard fastener engagement.

This tap is used in machine shop, production, and maintenance environments where 4-40 threaded holes are required in steel components. The plug chamfer style makes it the standard choice for through-hole applications on CNC machining centers, drill presses, and tapping machines. It is appropriate for use in light-duty production tapping as well as bench or hand-tapping with a proper tap handle where through-hole access is available.

Key Features

• Spiral point geometry pushes chips forward for through-hole tapping efficiency
• 3 flutes balanced for chip flow and rigidity in small-diameter taps
• Vanadium high speed steel (3% vanadium HSS) for enhanced wear resistance
• H5 thread limit for controlled tolerance in standard 4-40 thread fits
• Plug chamfer for straightforward entry in through-hole applications
• Bright finish compatible with a wide range of cutting fluids and lubricants

Compatibility

Designed for tapping 4-40 unified fine thread holes in steel and similar ferrous workpiece materials. Verify spindle speed, feed rate, and lubrication requirements for the specific material being tapped before use.

Installation Notes

Machinist or toolroom personnel should secure the workpiece and ensure the tap is aligned perpendicular to the hole axis before beginning the tapping cycle. Apply appropriate cutting fluid or tapping oil for the workpiece material to extend tool life and improve thread finish. Never force a tap that has stopped advancing — back off immediately to clear chip buildup and avoid breakage. For machine tapping, use a floating tap holder to compensate for any minor misalignment.