Hertel K010377AS25 Thread Forming Tap 5/16-18 Unc Plug Hss Tin

Product Description

The HERTEL K010377AS25 is a thread forming tap designed for right-hand, through-hole threading in standard UNC applications. Manufactured from high-speed steel with a titanium nitride (TiN) coating, this plug chamfer tap displaces material rather than cutting it, producing stronger threads with no chips to clear. It carries a 5/16-18 UNC thread specification, a 2B class of fit, and an H5 thread limit. Overall length is 2.7188 inches, with a thread length of 1.125 inches and a shank diameter of 0.3180 inches. The TiN coating reduces friction and extends tool life in ferrous and non-ferrous materials.

This tap is suited for production and maintenance applications requiring clean, chip-free internal threads in through-hole configurations. The plug chamfer, with 3 to 5 chamfered threads, makes it appropriate for through-holes where the tap can advance fully through the work. Machinists, tool-and-die tradespeople, and maintenance technicians use this tap in manual tap handles, drill presses, and CNC tapping cycles on materials compatible with thread forming rather than thread cutting.

Key Features

• Thread forming design displaces material to produce stronger, work-hardened threads with no chips
• Titanium nitride coating reduces friction and extends tool service life
• High-speed steel construction provides toughness for general-purpose tapping
• Plug chamfer with 3 to 5 chamfered threads optimized for through-hole applications
• H5 thread limit provides controlled tolerance for 2B class of fit
• Right-hand thread direction compatible with standard tapping equipment

Compatibility

Designed as an OEM-style replacement or direct-use thread forming tap for 5/16-18 UNC through-hole applications requiring a 2B class of fit and H5 thread limit.

Installation Notes

Thread forming taps require the correct forming tap drill size, which differs from standard cut tap drill sizes - consult a thread forming drill chart before drilling. Use a tapping fluid appropriate for the workpiece material to reduce galling and tool wear. Secure the workpiece fully before tapping and ensure the tap is aligned perpendicular to the work surface. Thread forming taps are not suitable for brittle materials such as cast iron or hardened steel.