Heli-coil 03CSB Spiral Point Sti Tap 3-48 Unc

Product Description

The HELI-COIL 03CSB is a spiral point STI tap designed for cutting threads in pre-drilled holes that will accept HELI-COIL wire thread inserts. Manufactured from high-speed steel with a bright, uncoated finish, this tap produces a 3-48 UNC thread form to the STI standard, which requires an oversized hole to accommodate the installed insert. With a plug chamfer and H1 thread limit, it is suited for threading through-hole applications in moderate-to-hard materials. Machining professionals and maintenance technicians install this tap wherever stripped or weak threads need permanent repair or original-equipment thread-insert installation.

This tap is used in thread repair and new-construction threading operations where a 3-48 UNC wire thread insert will be installed. It is appropriate for light-duty fastener applications found in precision assemblies, electronics enclosures, instrument housings, and thin-section metal components. The 2-flute spiral point geometry pushes chips forward ahead of the cutting zone, making it well suited for tapping blind or through holes in production and field-repair environments.

Key Features

• STI UNC thread standard sized for HELI-COIL wire thread insert installation
• High-speed steel construction provides durability across a range of workpiece materials
• Plug chamfer allows starting in a through hole without requiring a bottoming or taper lead
• H1 thread limit ensures controlled tolerance for proper insert fitment
• 2-flute spiral point design pushes chips forward to clear the cutting zone
• 3B class of fit delivers standard commercial thread accuracy

Compatibility

Designed for use with HELI-COIL wire thread inserts requiring a 3-48 UNC STI-tapped hole. Intended for use wherever a 3-48 UNC thread insert installation is specified in a through-hole or blind-hole application.

Installation Notes

A licensed machinist or maintenance technician should install this tap using a properly sized STI drill to prepare the hole before tapping. Always secure the workpiece and use appropriate cutting fluid to extend tap life and improve thread quality. Follow the thread insert manufacturer's torque and installation procedures for the wire insert after tapping. Deburr and clean the tapped hole before inserting the thread insert.