Hertel R837654 Extension Plug Tap 1/2-13 Unc 4 Flute Hss

Product Description

The HERTEL R837654 is a 1/2-13 UNC extension plug tap ground from high speed steel and finished bright/uncoated for general-purpose threading applications. With an 8-inch overall length, it provides the reach needed to thread holes in recessed or deep-cavity workpieces where a standard-length tap cannot access. The H3 thread limit and 4-flute geometry deliver consistent thread form and chip control in a wide range of materials. The 3B class of fit designation suits most standard fastener assemblies. A reduced shank measuring 0.367 inches in diameter allows use in standard tap holders and extension chucks. This tap is installed by machinists, tool and die makers, and maintenance trades working with UNC threads.

This extension tap is suited for threading operations in production machining, job shop, and maintenance-repair environments where 1/2-13 UNC threads are required in deep or obstructed holes. The plug chamfer distributes cutting load across the first few threads, making it a practical choice for through-holes and moderately deep blind holes. Its bright, uncoated surface is compatible with most cutting fluids and performs reliably in ferrous and non-ferrous materials at standard cutting speeds.

Key Features

• Extension length of 8 inches overall for reaching recessed or deep-cavity holes
• Plug chamfer for versatile use in through-holes and moderate-depth blind holes
• H3 thread limit for consistent fit in standard 3B tolerance assemblies
• 4-flute design promotes chip control and thread accuracy
• Reduced shank at 0.367 inches diameter fits standard extension tap holders
• High speed steel construction for durability across a broad range of workpiece materials

Compatibility

Designed as a direct-fit extension plug tap for 1/2-13 UNC threading operations using standard tap holders and extension chucks that accept a 0.367-inch reduced shank.

Installation Notes

This tap is installed by machinists or maintenance tradespeople using a tap wrench, extension chuck, or machine spindle set to appropriate speed for the workpiece material. Secure the workpiece and ensure proper alignment before starting the tap to avoid thread misalignment or tap breakage. Apply a suitable cutting fluid throughout the threading operation. Follow applicable shop safety procedures and manufacturer guidelines for tap speeds and feeds when using power equipment.