Kennametal 1544531 Hand Tap 1/4-20 Unc Bottoming Tin Hss

Product Description

The KENNAMETAL 1544531 is a 1/4-20 UNC straight flute hand tap designed for bottoming applications in ferrous metals. Built from high-speed steel with a titanium nitride (TiN) coating, it delivers extended tool life and reduced friction during threading operations. The 4-flute straight flute geometry provides chip control suited to through-hole and blind-hole bottoming work. With an overall length of 2.5 inches and a thread length of 1 inch, this tap is sized for standard 1/4-20 threading tasks. The H3 thread limit and Class 3B fit designation make it appropriate for close-tolerance threaded assemblies. Machinists and toolroom technicians install it by hand or with a tap wrench in bench and machine setups.

This tap is intended for threading operations in cast iron, stainless steel, and steel workpieces. Its bottoming chamfer allows thread cutting to the bottom of blind holes, making it a finishing tap used after a taper or plug tap has started the thread. Right-hand thread direction matches standard UNC fastener conventions. The TiN coating improves performance in harder ferrous materials where uncoated high-speed steel taps wear prematurely.

Key Features

• 1/4-20 UNC thread form, right-hand direction, Class 3B fit
• Bottoming chamfer for threading to the bottom of blind holes
• TiN coating reduces wear and extends tool life in ferrous materials
• H3 thread limit for close-tolerance 3B class threaded assemblies
• 4-flute straight flute design for chip control in cast iron, stainless steel, and steel
• Overall length of 2.5 inches with a 1-inch thread length

Compatibility

Rated for use in cast iron, stainless steel, and steel. Compatible with standard 1/4-20 UNC tap holders and tap wrenches. Designed as an OEM-style replacement or direct toolroom addition for 1/4-20 bottoming hand tap applications.

Installation Notes

Hand taps are installed by machinists or toolroom technicians using a tap wrench or tapping fixture. Secure the workpiece before tapping and ensure the starting hole is drilled to the correct tap drill size for 1/4-20 UNC threads. Apply cutting fluid appropriate for the workpiece material, particularly when tapping stainless steel. Do not force the tap; back off periodically to break chips and prevent tap breakage in blind holes.