Hertel G837651 Extension Tap 1/2-13 Hss Plug 4 Flutes H3

Product Description

The HERTEL G837651 is a 1/2-13 UNC extension tap designed for threading operations that require reach beyond what a standard-length tap provides. Built from high speed steel with a bright/uncoated finish, this plug chamfer tap delivers reliable thread-cutting performance in a range of ferrous and non-ferrous materials. The 4-flute geometry supports chip evacuation and stable tracking during through-hole and deep-hole tapping. The H3 thread limit and 3B class of fit make it well suited to production threading where consistent tolerance control is required. A reduced shank allows use in standard chuck setups. Machinists and toolroom technicians are the primary installers of this tooling.

This tap is used in machining centers, drill presses, and manual tapping setups where access depth demands an extended-length tool. The 1/2-13 UNC thread profile covers a widely used fastener size in structural, mechanical, and machine assembly work. The plug chamfer style — with 3 to 5 chamfered threads — is the standard choice for through-hole applications and general-purpose threading where a starting chamfer is not required. Its 4-inch overall length provides additional reach compared to standard hand tap configurations.

Key Features

• 1/2-13 UNC thread form with H3 thread limit for controlled tolerance output
• Plug chamfer geometry suited to through-hole tapping applications
• 4-flute design promotes chip evacuation and tool stability
• High speed steel construction provides durability across common workpiece materials
• Bright/uncoated finish — no heat treatment or coating that could affect dimensional tolerance
• Reduced shank diameter of 0.367 inches allows use in standard tap chucks and holders

Compatibility

Designed as an OEM-style replacement or direct tooling selection for any application requiring a 1/2-13 UNC plug chamfer extension tap with an H3 thread limit and 3B class of fit in standard tap holders or chucks accommodating a 0.367-inch reduced shank.

Installation Notes

Installation is performed by qualified machinists or toolroom personnel. Ensure the spindle or tapping head is fully powered down and the workpiece is securely fixtured before installing or changing the tap. Verify chuck and holder compatibility with the 0.367-inch reduced shank before seating. Use appropriate cutting fluid for the workpiece material to prolong tool life and improve thread quality.