Hertel 87003 Plug Hand Tap 5/16-24 Unf 4 Flute Hss

Product Description

The HERTEL 87003 is a 5/16-24 UNF plug hand pulley tap designed for cutting internal threads in through-holes and blind holes where the plug chamfer provides a practical starting point. Built from high speed steel with a bright finish, this tap features a 4-flute, right-hand configuration and an H3 thread limit for controlled tolerance fits. It measures 6 inches in overall length. Licensed machinists, pipefitters, and maintenance technicians reach for this tap when threading small-diameter fastener holes in metal components across HVAC, plumbing, and general mechanical applications.

This tap is suited for hand tapping operations on steel, cast iron, aluminum, and similar machinable metals. The plug chamfer — typically 3 to 5 threads of taper — allows it to start easily in a pre-drilled hole while still threading close to the bottom of a blind hole. It is commonly used in repair and fabrication work where 5/16-24 UNF thread engagement is required on brackets, pulleys, housings, and mechanical assemblies.

Key Features

• 5/16-24 UNF thread form for fine-pitch threading applications
• 4-flute design provides chip clearance and thread consistency
• Plug chamfer (3-5 thread lead) starts easily in pre-drilled through or blind holes
• High speed steel construction resists heat and wear during hand tapping
• Bright finish reduces friction and aids chip evacuation
• H3 thread limit ensures consistent tolerance for standard UNF fits
• Right-hand flute and cut for conventional clockwise threading

Compatibility

Designed as an OEM-style hand tap for use wherever 5/16-24 UNF internal threads are required in machinable metals during repair, maintenance, or fabrication work.

Installation Notes

This tap is intended for hand tapping operations using a standard tap wrench or T-handle. Always use cutting fluid appropriate for the workpiece material to extend tap life and improve thread quality. Ensure the pilot hole is drilled to the correct tap drill size for 5/16-24 UNF before starting. Reverse the tap periodically to break chips and prevent binding, especially in blind holes.