Osg 31440208 Spiral Point Sti Tap 4-40 Unc Plug

Product Description

The OSG 31440208 is a spiral point STI tap designed for threading 4-40 UNC threads in a plug chamfer configuration. It is manufactured from powdered metal and features a V finish for improved surface hardness and wear resistance. With 2 flutes, an overall length of 2 inches, and a shank diameter of 0.141 inches, this tap is built for through-hole tapping applications in ferrous and non-ferrous materials. It carries an H2 thread limit and a 2B class of fit, making it suitable for standard tolerance threaded assemblies. Machinists and tool-and-die professionals use this tap in production environments where consistent thread quality is required.

This tap is used in machine shop, maintenance, and light manufacturing settings where 4-40 UNC threads are required. The plug chamfer style makes it appropriate for through-hole applications where the tap can advance through the full thread depth. It is well suited for use in hand tapping or machine tapping setups on materials including mild steel, aluminum, and similar machinable metals. The Series 314Ti designation places it within OSG's STI tap line, designed for use with thread inserts.

Key Features

• 4-40 UNC thread size for fine-pitch, small-diameter threaded connections
• Plug chamfer style for through-hole tapping operations
• Powdered metal construction for improved wear life over high-speed steel
• V finish applied for added surface hardness and lubricity
• H2 thread limit with 2B class of fit for standard tolerance threads
• Spiral point geometry pushes chips forward, reducing clogging in through-hole applications

Compatibility

Designed as an OEM-style STI tap replacement for use in through-hole tapping of 4-40 UNC threads where thread inserts are installed.

Installation Notes

This tap should be installed and used by qualified machinists familiar with tapping feeds, speeds, and cutting fluid requirements for the workpiece material. Always secure the workpiece and ensure proper alignment before tapping to avoid tap breakage. Use appropriate cutting fluid for the material being tapped. Power down any machine tapping setup before changing or inspecting tooling.