Osg 34300508 Spiral Flute Sti Tap M5x0.80 Vanadium Hss

Product Description

The OSG 34300508 is a spiral flute STI (Screw Thread Insert) tap designed to cut metric coarse internal threads for Heli-Coil and similar wire thread insert applications. Manufactured from vanadium high-speed steel with a V finish coating, this tap handles the demanding tolerances required for STI thread profiles. The 45-degree helix angle evacuates chips efficiently upward through the flutes, making it well suited for blind-hole applications. A modified bottoming chamfer allows threading closer to the bottom of a hole than a standard taper or plug chamfer. Thread class of fit is 6H, appropriate for precision metric fastener applications. Licensed machinists, toolmakers, and maintenance technicians use this tap in both manual and CNC tapping operations.

This tap is intended for cutting M5x0.80 metric coarse STI threads in ferrous and non-ferrous materials where a thread insert will be installed. It is a right-hand flute, right-hand thread tool in the OSG Series 343STI. With a 1-inch thread length and 2.5-inch overall length, it fits standard tap holders and tapping heads used in machine shops, production floors, and field maintenance environments. The 6H thread limit (D3) ensures the oversized thread profile needed to accept wire thread inserts at final nominal thread size.

Key Features

• M5x0.80 metric coarse STI thread profile for wire thread insert applications
• 45-degree helix angle promotes upward chip evacuation in blind holes
• Modified bottoming chamfer for threading close to the bottom of a blind bore
• Vanadium high-speed steel construction for wear resistance and toughness
• 6H class of fit with D3 thread limit for accurate STI oversize tolerance
• Right-hand flute and right-hand thread for use in standard tapping setups

Compatibility

Designed as an STI tap for use with M5x0.80 metric coarse wire thread inserts such as Heli-Coil style inserts. Part of the OSG Series 343STI product family. Fits standard tap holders accepting a 0.255-inch shank diameter.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tap wrench, tapping stand, or CNC tapping cycle. Always use appropriate cutting fluid for the workpiece material and ensure the tap is properly aligned to the drilled hole before engagement. Confirm the correct STI drill size has been used prior to tapping, as an undersized pilot hole will damage the tap. Follow the tool manufacturer and insert manufacturer guidelines for drill size, tap depth, and insert installation sequence.