Heli-coil 1CPB Hand Sti Tap 12-24 Unc H2 Plug Chamfer

Product Description

The HELI-COIL 1CPB is a hand STI tap designed to cut threads for helical coil thread insert installation in 12-24 UNC tapped holes. STI taps cut an oversized thread profile that accepts standard wire thread inserts, restoring stripped or damaged threads to original spec or adding insert-ready threads in new material. This tap features a plug chamfer, three flutes, and an H2 thread limit for controlled tolerance. The body is machined from high speed steel with a bright finish, making it a reliable choice for shop and field thread repair work.

This tap is used in thread repair and insert installation applications across manufacturing, maintenance, and repair environments. It is appropriate for hand tapping operations in metals and other machinable materials where a 12-24 UNC thread insert is required. The plug chamfer allows starting in through-holes or where moderate lead-in is acceptable. Licensed HVAC techs, millwrights, machinists, and field service technicians commonly use STI taps when restoring threads in equipment housings, brackets, and similar components.

Key Features

• STI thread profile cuts oversized holes sized for helical coil wire thread inserts
• 12-24 UNC thread form with H2 thread limit for consistent fit tolerance
• Plug chamfer for reliable lead-in on through-holes and moderate blind-hole starts
• Three flutes for efficient chip evacuation during hand tapping
• High speed steel construction for durability across a range of machinable materials
• Bright finish with 0.3180-inch shank diameter and 3/8-inch square drive length

Compatibility

Designed for use with standard helical coil thread inserts in 12-24 UNC applications requiring an STI oversized tap. Class of fit 3B.

Installation Notes

This tap is intended for hand tapping operations and should be used with an appropriate tap wrench sized for the 0.2380-inch square drive. Secure the workpiece before tapping and apply cutting fluid appropriate for the workpiece material to extend tool life and improve thread quality. Back the tap out periodically to break chips and clear flutes. Follow the insert manufacturer's installation instructions for proper insert depth and drive tool use after tapping.