Kennametal 5416880 Spiral Point Tap 1/4-28 Unf Hss-e Oxide

Product Description

The KENNAMETAL 5416880 is a spiral point tap designed for through-hole threading operations in 1/4-28 UNF applications. Built from High-Speed Steel-E (HSS-E) with an oxide coating, it delivers controlled chip evacuation by pushing chips ahead of the cutting edge rather than packing them into the flute. The plug chamfer provides a gradual thread lead-in across several thread starts, making it well-suited for through-hole work where the tap can advance freely. With a thread limit of H3 and a Class 3B fit, the tap produces threads within the tolerance range required for close-fitting fastener assemblies. Machinists, toolroom techs, and maintenance professionals working in steel, stainless steel, and cast iron applications rely on this geometry for consistent, repeatable thread quality.

The 5416880 is intended for through-hole threading in ferrous materials including steel, stainless steel, and cast iron. Its spiral point style is best applied in production and maintenance environments where chip clearance through the bottom of the hole is available. The 2.5-inch overall length provides adequate reach for standard workpiece thicknesses, and the 0.625-inch thread length suits typical fastener engagement depths at this thread size. It is used in manual tapping, CNC tapping, and drill press tapping setups where the spindle can maintain axial alignment.

Key Features

• Spiral point geometry pushes chips forward through the hole, reducing chip packing in through-hole applications
• HSS-E construction offers improved toughness and wear resistance compared to standard HSS for ferrous materials
• Oxide coating reduces friction and provides light corrosion resistance during storage and use
• Plug chamfer with gradual thread lead-in supports consistent thread starts in through-hole work
• H3 thread limit and Class 3B fit for close-tolerance thread production in steel and stainless steel
• 3-flute design balances chip space and tool body strength at the 1/4-28 UNF size

Compatibility

Designed for through-hole threading in steel, stainless steel, and cast iron. Part of the KENNAMETAL T820 series. Produces 1/4-28 UNF Class 3B internal threads.

Installation Notes

Installation is performed by machinists or maintenance technicians using a tap handle, tapping head, or rigid CNC tapping cycle. Ensure the workpiece is securely fixtured and that the tap is properly aligned with the drilled hole before starting the thread. Apply appropriate tapping fluid or cutting oil for the workpiece material, particularly when threading stainless steel. Do not reverse-cycle the tap without verifying chip clearance, and do not exceed the torque capacity of the tap shank when operating in hard or interrupted materials.