Hertel G837586 Extension Tap 1/4-28 Unf 2 Flute Hss

Product Description

The HERTEL G837586 is a spiral point plug extension tap designed for threading 1/4-28 UNF right-hand internal threads in through-hole applications. Built from high speed steel with a bright, uncoated finish, this tap features a 2-flute spiral point geometry that pushes chips ahead of the cut rather than backing them into the flute. The H3 thread limit holds tight tolerances for a 3B class of fit, making it suitable for precision threaded assemblies. At 6 inches overall length, the extended reach allows machinists and maintenance techs to tap threads in recessed bores or hard-to-access locations where a standard-length tap cannot reach.

This tap is suited for production and maintenance machining environments where 1/4-28 UNF threads are required in deep or recessed through-hole features. The spiral point plug chamfer drives chips forward, making it the preferred choice for through-hole work in steel, aluminum, and similar machinable materials. It is installed by machinists and tool-and-die professionals using standard tap handles, tapping attachments, or CNC rigid-tapping setups.

Key Features

• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• H3 thread limit for consistent 3B class of fit tolerances
• High speed steel construction for durability across common machinable materials
• Bright, uncoated finish suitable for use with standard cutting fluids
• 6-inch overall length provides extended reach into deep or recessed bores
• Reduced shank design accommodates standard tap holders

Compatibility

Designed as an OEM-style replacement and standard tooling option for applications requiring 1/4-28 UNF right-hand internal threads in through-hole configurations with a 3B class of fit.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician. Ensure the workpiece is securely fixtured and the spindle or tap handle is properly aligned to the hole axis before engaging the tap. Apply appropriate cutting fluid for the workpiece material to prolong tool life and improve thread quality. Inspect the tap for wear or chipping before each use, and never force a tap that has stalled to avoid breakage.