Heli-coil 2CBB Hand Sti Tap 8-32 Unc H2 3 Flutes

Product Description

The HELI-COIL 2CBB is a hand STI (Screw Thread Insert) tap designed to cut the oversized internal threads required for helical coil thread insert installation. Built from high-speed steel with a bright, uncoated finish, this tap produces a 3B class-of-fit thread in an 8-32 UNC configuration with an H2 thread limit. The bottoming chamfer allows threading close to the bottom of a blind hole, a critical requirement in repair and fabrication applications. Three flutes provide adequate chip clearance for hand tapping in steel, aluminum, and similar materials. Overall length is 2.375 inches with a thread length of 0.9375 inches.

This tap is used when installing helical wire thread inserts to restore or reinforce damaged, stripped, or weak threads in base materials. It is well suited for maintenance and repair work in HVAC equipment, mechanical assemblies, and industrial machinery where stripped fastener holes need to be rebuilt to original or stronger specifications. The bottoming chamfer style makes it particularly useful in shallow or blind-hole applications where a plug or taper chamfer tap would leave insufficient fully formed threads.

Key Features

• STI thread form cuts oversized hole to accept helical coil thread inserts
• Bottoming chamfer allows threading to within a few threads of the bottom of blind holes
• H2 thread limit for consistent 3B class-of-fit results
• High-speed steel construction for durability across common base materials
• 3-flute design provides chip clearance for controlled hand tapping
• Bright uncoated finish - no coating buildup that could affect thread tolerance

Compatibility

Designed for use with helical coil thread insert systems requiring an 8-32 UNC STI tap with H2 thread limit and bottoming chamfer geometry.

Installation Notes

This tap is intended for hand use by machinists, maintenance technicians, and trade professionals performing thread repair. Secure the workpiece firmly before tapping and use a calibrated tap handle to maintain axial alignment. Apply appropriate cutting fluid for the base material being tapped. Back the tap out periodically to clear chips, especially in blind holes, to prevent tap breakage.