Kennametal 5455239 Spiral Point Tap 4-40 Unc Plug Chamfer Hss-e

Product Description

The KENNAMETAL 5455239 is a spiral point tap designed for through-hole threading in ferrous and ferrous-alloy workpieces. It cuts a 4-40 UNC thread profile using a 2-flute, plug chamfer geometry that pushes chips forward ahead of the cutting zone, keeping the flutes clear during tapping. Built from HSS-E (high-speed steel with cobalt content) at material grade KSP39 and finished with an oxide coating, this tap handles steel, stainless steel, and cast iron at production volumes. The right-hand H2 thread limit and 2B/3B class of fit make it a standard choice for general-purpose fastener holes in light-gauge assemblies and instrument-scale hardware.

This tap is sized for small-diameter through-hole applications where a 4-40 UNC thread is specified. At 1.875 inches overall length with a 13.00 mm (0.510 inches) thread length, it seats in standard tap holders and hand tap wrenches used in precision machining, electronics enclosure assembly, and instrument manufacturing. The plug chamfer provides a gradual cut-in appropriate for mid-run starting in pre-drilled through holes. No coolant-through feature is present, so flood or brush-applied cutting fluid is the standard approach for stainless and cast iron applications.

Key Features

• Spiral point geometry pushes chips forward, reducing chip packing in through-hole applications
• HSS-E (cobalt-enhanced high-speed steel) construction at material grade KSP39 for elevated heat and wear resistance
• Oxide coating reduces friction and provides light corrosion protection during storage and use
• H2 thread limit with 2B/3B class of fit suits standard tolerance through-hole fastener applications
• Right-hand, 2-flute plug chamfer design for controlled entry and consistent thread form
• Compact 1.875-inch OAL fits standard small-tap holders and hand wrenches without extension

Compatibility

Designed for through-hole threading in steel, stainless steel, and cast iron workpieces requiring a 4-40 UNC thread form. Part of the Kennametal T820 series.

Installation Notes

This tap is installed by licensed machinists or precision assembly technicians using standard tap handles or CNC tapping attachments sized for the 3.58 mm (0.141 inches) shank diameter. Always ensure the workpiece is properly secured and the pre-drilled hole diameter matches the correct tap drill size for a 4-40 UNC thread before starting. Apply appropriate cutting fluid, particularly when tapping stainless steel or cast iron, to extend tool life and maintain thread quality. Do not reverse-tap or force entry if the tap binds — back out, clear chips, and re-apply cutting fluid.