Accupro T1620162B Spiral Point Tap 4-40 Plug 2B

Product Description

The ACCUPRO T1620162B is a spiral point tap designed for cutting 4-40 unified fine threads in through-hole applications. Built from 3% vanadium high-speed steel with an oxide coating, it delivers consistent thread quality in ferrous materials including stainless steel. The plug chamfer style guides the tap into the workpiece with a gradual lead-in, making it well suited for through-hole threading on production runs and repair work alike. This tap is used by machinists, maintenance technicians, and tool-and-die professionals who require reliable thread formation in small-diameter fastener applications.

This tap is intended for through-hole tapping where chips can be pushed forward and clear of the cutting zone. Its 3-flute spiral point geometry is particularly effective in stainless steel and other materials that produce stringy chips. The 2B class of fit produces standard commercial-grade threads compatible with 4-40 fastener assemblies found in electronic enclosures, precision instruments, and light mechanical assemblies. Right-hand thread direction is standard for conventional tapping operations.

Key Features

• 4-40 thread size with 2B class of fit for standard commercial thread tolerance
• 3-flute spiral point geometry pushes chips forward, ideal for through-hole tapping
• Plug chamfer provides gradual lead-in for controlled thread cutting
• 3% vanadium high-speed steel construction for wear resistance in stainless steel applications
• Oxide coating reduces friction and improves chip flow at the cutting edge
• Right-hand thread direction, no coolant-through requirement

Compatibility

Designed for through-hole tapping of 4-40 threads in stainless steel and similar ferrous materials. Fits standard tap holders and tapping heads accepting 3.58 mm shank diameters.

Installation Notes

Tapping should be performed by a qualified machinist using a properly aligned tap wrench, drill press, or CNC tapping cycle. Ensure the pilot hole is drilled to the correct diameter for a 4-40 thread before tapping. Use an appropriate cutting fluid for stainless steel to reduce heat buildup and extend tap life. Never force a tap that has stopped turning, as breakage in stainless steel is difficult to recover from.