Kennametal 5443804 Spiral Flute Tap 4-40 Bottoming Hss

Product Description

The KENNAMETAL 5443804 is a spiral flute tap designed for cutting 4-40 UNC internal threads in bottoming applications. It features 2 flutes with a fast flute style and a 45-degree helix angle, which helps evacuate chips efficiently in blind-hole operations. The tap is manufactured from vanadium high speed steel and finished with an oxide coating to reduce friction and extend service life. With an overall length of 1.88 inches and a thread length of 0.51 inches (13 mm), this tap is sized for small-diameter precision work. It carries a 2B/3B class of fit, making it suitable for standard and close-tolerance threaded assemblies. Machinists, tool-and-die makers, and maintenance technicians use this tap in CNC and manual tapping operations.

This tap is intended for right-hand threading in steel, stainless steel, and cast iron workpieces. The bottoming chamfer style allows threading close to the bottom of blind holes where full thread engagement is required. The H2 thread limit designation supports consistent fit across production runs. It is well-suited to small-frame fastener applications common in instrument assemblies, electrical enclosures, and precision mechanical components requiring 4-40 threaded holes.

Key Features

• Bottoming chamfer style for threading to the bottom of blind holes
• 45-degree helix angle with fast flute style for efficient chip evacuation
• Oxide coating reduces friction and improves tap life in ferrous materials
• H2 thread limit for consistent 2B/3B class of fit
• Right-hand thread and right-hand flute direction
• No coolant-through design — suitable for standard tapping with cutting fluid applied externally

Compatibility

Designed for tapping 4-40 UNC threads in steel, stainless steel, and cast iron. Primary workpiece material codes P, M, and K confirm suitability across carbon steel, stainless steel, and cast iron applications.

Installation Notes

This tap should be installed and operated by a qualified machinist or maintenance technician. Before tapping, ensure the workpiece is securely fixtured and the correct tap drill size for 4-40 is used to prepare the hole. Apply cutting fluid appropriate for the workpiece material before and during the tapping operation. Inspect the tap for wear or chipping before each use, and never reverse a broken tap without proper extraction tooling.