Hertel K007062AS Spiral Point Sti Tap 5/16-18 Unc

Product Description

The HERTEL K007062AS is a spiral point STI tap designed for cutting threads in steel insert (STI) applications using the 5/16-18 UNC thread form. Built from high-speed steel with a bright, uncoated finish, this plug chamfer tap is suited for through-hole tapping operations where chip evacuation is critical. The spiral point geometry pushes chips ahead of the cutting action rather than backing them out, reducing chip packing and improving cutting efficiency. At 2.9375 inches overall length with a 0.3125 inch thread length, it fits standard tap holders and machine spindles used in production and maintenance environments. Machinists, tool and die makers, and MRO technicians are the primary users.

This tap is specifically designed for STI (Screw Thread Insert) applications, where the oversized thread it cuts accepts a helical coil insert to restore or create standard 5/16-18 UNC fastener threads. It is used in repair work on stripped or damaged threads in metal components as well as in original equipment manufacturing where threaded inserts are specified by design. The plug chamfer configuration makes it appropriate for through-hole work or for starting threads in blind holes where adequate clearance exists at the bottom.

Key Features

• Spiral point geometry pushes chips forward, reducing clogging in through-hole tapping
• STI UNC thread form — produces oversized threads sized for helical coil inserts
• 5/16-18 UNC thread size with H3 thread limit for controlled fit with standard inserts
• High-speed steel construction provides hardness and wear resistance across common workpiece materials
• Plug chamfer allows easy thread starting and suits through-hole applications
• Helicoil Reference Number 5CSB for cross-reference with insert tooling systems

Compatibility

Designed for use in STI UNC thread insert applications requiring a 5/16-18 oversized tap with H3 thread limit. Referenced as Helicoil Reference Number 5CSB. Confirm compatibility with your specific insert system and workpiece material before use.

Installation Notes

This tap is installed and used by machinists and maintenance technicians in manual or CNC tapping setups. Secure the workpiece fully before tapping and ensure proper alignment to avoid tap breakage. Apply appropriate cutting fluid for the workpiece material to extend tool life and improve thread quality. Do not force the tap — if resistance increases unexpectedly, back out to clear chips before continuing.