Hertel R867177 Extension Tap 3/4-10 Unc 3 Flute H3 Hss

Product Description

The HERTEL R867177 is a spiral point plug extension tap designed for cutting right-hand internal threads in a range of metalworking applications. Built from high speed steel with a bright uncoated finish, it cuts a 3/4-10 UNC thread profile to an H3 tolerance limit. The three-flute spiral point design pushes chips forward ahead of the tap, reducing clogging in through-hole applications. With an overall length of 6 inches, this extension tap reaches deeper into workpieces or fixtures where a standard-length tap cannot access the thread start. It features a reduced shank for use in standard tap holders and extension sets. Machinists and tool and die technicians rely on this geometry for consistent thread quality in production and repair environments.

This tap is suited for through-hole tapping operations in materials compatible with high speed steel tooling, including mild steels, aluminum alloys, and similar machinable metals. The plug chamfer — typically 3 to 5 threads — makes it appropriate for starting a thread in a pre-drilled through hole. The 6-inch overall length makes it practical for deep fixture work, extended reach setups, or applications where standard-length taps cannot clear surrounding material or tooling. It is sold and packaged individually.

Key Features

• Spiral point (gun tap) geometry pushes chips forward, ideal for through-hole tapping
• H3 thread tolerance limit for consistent fit within standard UNC tolerance range
• High speed steel construction provides good wear resistance across common machinable metals
• 6-inch overall length extends reach into deep fixtures or obstructed workholding setups
• Reduced shank allows compatibility with standard tap holders and extension tooling
• Bright uncoated finish — no coating buildup risk in tapped threads

Compatibility

Designed for use in standard tap holders and extension sets that accept a reduced shank configuration; suitable for through-hole tapping of 3/4-10 UNC threads in production machining and maintenance repair operations.

Installation Notes

This tap is installed and operated by machinists using a tap wrench, tapping head, or CNC rigid tapping setup rated for the thread size. Ensure the workpiece is securely fixtured and the pilot hole diameter matches the correct tap drill size for 3/4-10 UNC before threading begins. Use appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. Never reverse a spiral point tap under power without confirming the machine cycle supports reversal.