Osg 7004400 Spiral Point Sti Tap 4-48 Unf 2 Flute Hss

Product Description

The OSG 7004400 is a spiral point STI tap designed for cutting 4-48 UNF threads in preparation for Heli-Coil or similar wire thread insert installations. Built from high-speed steel (HSS) with a bright/uncoated finish, this plug-chamfer tap is suited for through-hole tapping applications where chip evacuation is a priority. The spiral point geometry pushes chips forward ahead of the cutting teeth, reducing the risk of chip packing in blind or deep holes. With an overall length of 1.875 inches and a thread length of 9/16 inches, the 7004400 fits standard tap holders and handles used in maintenance, repair, and production machining environments. Installation is performed by machinist or maintenance technicians.

This tap is used in applications requiring STI (Screw Thread Insert) thread preparation, specifically for 4-48 UNF fastener systems. It is commonly used when repairing stripped threads in aluminum, steel, and similar materials, or when engineering a stronger threaded connection using a wire thread insert. The plug chamfer style makes it appropriate for through-holes and starting threads in open bores. Helicoil reference number 04FSA applies to this tap, confirming its intended use with standard Heli-Coil insert systems in that thread size.

Key Features

• Spiral point geometry pushes chips forward, reducing packing in through-hole applications
• Plug chamfer provides a gradual thread lead-in, suitable for through-hole tapping
• High-speed steel construction handles a broad range of workpiece materials
• H2 thread limit provides tight tolerance control for consistent insert fitment
• Bright/uncoated finish - no coating buildup to alter cutting geometry
• Helicoil reference 04FSA confirmed for Heli-Coil wire thread insert compatibility

Compatibility

Designed for use with Heli-Coil wire thread insert systems; Helicoil reference number 04FSA. Intended for tapping 4-48 UNF STI threads in through-hole configurations using standard tap holders.

Installation Notes

Installation is performed by machinists or maintenance technicians using a standard tap wrench, hand tap holder, or low-speed tapping attachment. The workpiece should be secured and the correct STI drill size used prior to tapping. Apply cutting fluid appropriate to the workpiece material to extend tool life and improve thread finish. Follow the insert manufacturer's specifications for drill diameter and tap depth to ensure proper insert engagement.