Kennametal 5455891 Spiral Point Tap 12-28 Unf Hss-e Oxide

Product Description

The KENNAMETAL 5455891 is a spiral point tap designed for through-hole threading in a 12-28 UNF thread form. It is manufactured from HSS-E (high-speed steel with cobalt enhancement), which provides elevated heat and wear resistance compared to standard HSS. An oxide coating adds additional lubricity and corrosion protection. The tap features a plug chamfer for standard through-hole entry and a right-hand thread direction with an H3 thread limit, targeting a 2B/3B class of fit. With a 2-flute configuration and spiral point geometry, it pushes chips forward ahead of the cut, making it suited for production tapping in through-hole applications.

This tap is intended for through-hole threading operations in steel, stainless steel, and cast iron. The 12-28 UNF designation covers fine-thread fastener holes common in precision mechanical assemblies, instrumentation, and light structural applications. It is appropriate for use in CNC machining centers, drill presses, and tapping heads where through-hole conditions allow forward chip evacuation. The T820 series is designed for production environments where consistent thread quality and tool life are required. Machinists and toolroom technicians are the primary users.

Key Features

• Spiral point geometry pushes chips forward for efficient through-hole evacuation
• HSS-E (cobalt-enhanced high-speed steel) construction for improved heat and wear resistance
• Oxide coating provides lubricity and surface protection during tapping
• Plug chamfer for standard through-hole entry and lead-in
• H3 thread limit targeting 2B/3B class of fit for general-purpose UNF threads
• No coolant-through requirement — compatible with flood or brush-applied cutting fluid

Compatibility

Designed for through-hole threading in steel, stainless steel, and cast iron workpieces requiring a 12-28 UNF thread form with a 2B/3B class of fit. Part of the KENNAMETAL T820 series.

Installation Notes

This tap should be installed and operated by qualified machinists familiar with tapping speeds, feeds, and cutting fluid requirements for the workpiece material. Power down and de-energize any machine tool before loading or changing tooling. Use an appropriate tap holder or floating chuck to reduce axial loading and prevent tap breakage. Always verify hole depth and through-hole clearance before tapping to ensure chip evacuation is unobstructed.