Hertel K008864AS 5/16-18 Unc 4 Flute Plug Tap Hss

Product Description

The HERTEL K008864AS is a 5/16-18 UNC plug hand pulley tap designed for cutting internal threads in through-holes and blind holes where thread engagement runs close to the bottom. Manufactured from high speed steel with a bright finish, this 4-flute tap provides clean thread cutting in a range of ferrous and non-ferrous materials. The H3 thread limit designation indicates a controlled tolerance class suited for standard UNC thread fits. At 6 inches overall length and a 0.318-inch shank diameter, the tool is sized for use in hand tap wrenches and standard machine setups. It is a standard choice for machinists, maintenance technicians, and tool-and-die professionals who need a reliable plug tap for 5/16-18 work.

This tap is appropriate for general-purpose threading applications in light manufacturing, maintenance and repair operations, and fabrication shops. The plug chamfer — typically 3 to 5 threads — allows it to start easily in a hole and continue threading with minimal resistance. It is well suited for through-holes and for blind holes where full thread depth is not required at the very bottom of the bore. Professionals working in HVAC equipment fabrication, electrical enclosure assembly, and mechanical maintenance will find this a standard utility tap for 5/16-18 fastener applications.

Key Features

• 5/16-18 UNC thread form for standard unified coarse-pitch threading
• 4-flute design provides balanced cutting action and chip distribution
• High speed steel construction for durability across a range of workpiece materials
• Bright finish suitable for general-purpose dry and lubricated tapping
• H3 thread limit for controlled tolerance fit on standard UNC fasteners
• 6-inch overall length accommodates hand tap wrenches and machine holders

Compatibility

Designed as a standard 5/16-18 UNC plug tap compatible with hand tap wrenches and machine tap holders sized for a 0.318-inch shank diameter.

Installation Notes

This tap is installed by a machinist or maintenance technician using a hand tap wrench or tapping head. Always drill the correct tap drill size for 5/16-18 UNC before tapping and ensure the hole is properly deburred. Apply cutting fluid appropriate to the workpiece material to extend tool life and improve thread quality. Reverse the tap periodically during hand tapping to break chips and prevent tap breakage.