Hertel K015916AS Extension Pipe Tap 1/4-18 Npt Hss

Product Description

The HERTEL K015916AS is a high-speed steel extension pipe tap designed for cutting 1/4-18 NPT internal threads in pipe fittings, valves, and threaded port applications. With an overall length of 8 inches, it reaches into recessed or deep-set bosses that standard-length taps cannot access. The plug chamfer provides a smooth lead-in with 3 to 5 chamfered threads, making it well-suited for through-hole and moderately blind NPT tapping operations. The bright, uncoated finish is appropriate for general-purpose HSS tooling used across a range of materials. Machinists, pipefitters, and maintenance technicians working on pipe assemblies are the primary users of this tool.

This extension tap is used wherever a 1/4-18 NPT threaded connection must be cut or re-chased in a location that a standard-length tap cannot reach. Typical applications include tapping pipe ports in manifolds, valve bodies, and machined blocks in HVAC, plumbing, and industrial maintenance settings. The 4-flute geometry provides adequate chip clearance for most ferrous and non-ferrous metals encountered in trade and light industrial work. The extended shank allows use in drill presses, tapping heads, and hand-tap wrenches capable of accommodating the shank diameter.

Key Features

• 1/4-18 NPT thread form for standard tapered pipe thread connections
• 8-inch overall length for reaching deep or recessed tapping locations
• 4 flutes for balanced chip evacuation in general-purpose materials
• Plug chamfer with 3 to 5 lead threads for controlled thread engagement
• High-speed steel construction for durability across a range of workpiece materials
• Bright, uncoated finish — no coating concerns for sensitive material applications

Compatibility

Designed for cutting 1/4-18 NPT internal threads in through-hole and accessible blind-hole applications where an extended-reach tap is required. Compatible with standard tap wrenches, tapping heads, and drill press setups that accept the 0.3120-inch shank diameter.

Installation Notes

Tapping operations should be performed by a qualified machinist or pipefitter familiar with NPT thread standards and proper cutting fluid use. Always secure the workpiece firmly and ensure the tap is properly aligned to the bore centerline before applying torque to avoid tap breakage. Apply appropriate cutting fluid for the workpiece material throughout the tapping operation. NPT threads are tapered — do not force the tap beyond the designed thread engagement depth.