Heli-coil 4763-2.5 Spiral Point Sti Tap M2.5x0.45

Product Description

The HELI-COIL 4763-2.5 is a spiral point STI tap designed for cutting M2.5 x 0.45 metric coarse threads in preparation for HELI-COIL thread insert installation. Manufactured from high-speed steel with a bright, uncoated finish, this plug-chamfer tap features 2 flutes and conforms to a 5H class of fit with a D2 thread limit. The overall length is 1-15/16 inches with a thread length of 5/8 inches. It is the correct tool to use when threading a parent material hole to accept a wire thread insert, restoring or creating load-bearing threads in aluminum, cast iron, and other materials common in mechanical and industrial assemblies.

This tap is used specifically in STI (Screw Thread Insert) applications where standard thread dimensions are undersized to accommodate the wall thickness of a HELI-COIL insert. The plug chamfer makes it suited for through-hole tapping and most general-purpose threading operations. Typical install scenarios include aerospace component repair, automotive engine work, and precision equipment maintenance where thread stripping or damage requires reliable insert-based repair using the M2.5 x 0.45 thread size.

Key Features

• STI metric coarse thread profile sized for M2.5 x 0.45 HELI-COIL insert installation
• High-speed steel construction for durability across a range of workpiece materials
• Plug chamfer allows use in through-holes and most standard tapping applications
• 5H class of fit with D2 thread limit for accurate, consistent thread geometry
• 2-flute design provides chip clearance in typical threading operations
• Bright, uncoated finish suitable for use with standard cutting fluids

Compatibility

Designed for use with HELI-COIL M2.5 x 0.45 metric coarse wire thread inserts. This tap produces the oversized STI thread profile required before insert installation and is not interchangeable with standard M2.5 x 0.45 taps.

Installation Notes

This tap should be installed by a machinist or trained technician familiar with thread insert repair procedures. Always secure the workpiece and use appropriate cutting fluid for the parent material before tapping. Follow the HELI-COIL system sequence: drill to the correct insert drill size, tap with this STI tap, then install the insert using the appropriate insertion tool. Do not use this tap in place of a standard M2.5 x 0.45 tap, as the resulting thread will not accept a standard fastener directly.