Kennametal 1540453 Spiral Point Tap 4-40 Unc Hss Bottoming

Product Description

The KENNAMETAL 1540453 is a spiral point tap designed for cutting internal threads in through-hole and bottoming applications. Built from high speed steel (HSS) with a bright, uncoated finish, this tap produces a 4-40 UNC thread form with a right-hand thread direction. The bottoming chamfer allows threading close to the bottom of a blind hole. With 2 flutes and an H2 thread limit, it holds tight tolerances suitable for 2B and 3B class-of-fit requirements. Licensed machinists, tool-and-die workers, and maintenance technicians use this tap in production and repair work involving small-diameter fastener threads.

This tap is suited for use in cast iron and non-ferrous metals such as aluminum, brass, and copper. The spiral point geometry pushes chips forward ahead of the cutting zone, making it effective in through-hole applications where chip evacuation is straightforward. At 1.875 inches overall length with a 0.563-inch thread length and a 0.141-inch shank diameter, it fits standard tap holders and chucks used for small fractional-inch tapping operations in both manual and CNC-assisted setups.

Key Features

• 4-40 UNC thread form with right-hand cutting direction
• Bottoming chamfer for threading close to the base of a blind hole
• H2 thread limit for consistent 2B and 3B class-of-fit tolerances
• High speed steel construction provides durability in cast iron and non-ferrous metals
• Bright uncoated finish — no coating buildup to affect thread dimensions
• Spiral point flute design advances chips forward to keep the cutting zone clear

Compatibility

Designed as an OEM-style cutting tool replacement for applications requiring a 4-40 UNC spiral point tap in high speed steel with an H2 thread limit and bottoming chamfer. Material applications include cast iron and non-ferrous metals as specified by the manufacturer.

Installation Notes

This tap is installed and operated by machinists, toolmakers, or maintenance technicians using a standard tap wrench, tapping head, or CNC rigid-tapping setup sized for small-diameter taps. Always secure the workpiece and confirm the pilot hole diameter matches the recommended tap drill size for 4-40 UNC before beginning. Apply appropriate cutting fluid for the workpiece material to extend tap life and improve thread quality. Do not exceed the tap's rated capacity by forcing it through harder materials than specified.