Osg 34200401 Spiral Point Sti Tap M4 X 0.7 3 Flutes

Product Description

The OSG 34200401 is a spiral point STI tap designed for threading STI metric coarse holes in a plug chamfer configuration. Built from vanadium high-speed steel with an oxide finish, this tap produces M4 x 0.7 threads in Heli-Coil or similar STI insert applications. It carries a 6H class of fit and a D3 thread limit, making it suitable for close-tolerance production work. The overall length is 2-3/8 inches with a thread length of 15/16 inches and a shank diameter of 0.2200 inches. Machinists and tool-and-die professionals use this tap in hand-tapping operations and machine tapping setups where controlled thread geometry is required.

This tap is used in manufacturing, maintenance, and repair applications where STI metric coarse threads are needed for insert preparation. The spiral point design pushes chips forward ahead of the cutting zone, making it well suited for through-hole tapping. It is appropriate for use in ferrous and non-ferrous materials where a plug chamfer entry is acceptable. The 3-flute geometry provides good chip clearance at this thread size.

Key Features

• M4 x 0.7 STI metric coarse thread form for Heli-Coil and similar insert applications
• Vanadium high-speed steel construction for wear resistance and toughness
• Oxide finish for basic lubrication retention during cutting
• Plug chamfer for standard through-hole entry
• 6H class of fit with D3 thread limit for close-tolerance work
• Spiral point geometry pushes chips forward, reducing clogging in through-hole applications

Compatibility

Designed as an OEM-style replacement tap compatible with standard machine tapping chucks and holders accepting a 0.2200-inch shank diameter for STI metric coarse thread applications.

Installation Notes

This tap should be installed by a qualified machinist or toolroom professional familiar with STI threading procedures. Use appropriate tapping fluid for the workpiece material and ensure the tap is properly aligned to avoid breakage at this small diameter. Secure the workpiece before operation and confirm spindle speed settings are appropriate for the material and tap size before engaging. Never force a tap that has stopped cutting freely.