Osg 1707701 Spiral Point Tap 5/16-24 Unf Plug 3 Flute

Product Description

The OSG 1707701 is a spiral point tap designed for cutting 5/16-24 UNF internal threads in demanding materials including hardened steel, stainless steel, high-nickel alloy, and titanium. Built from powdered metal with a steam oxide coating, this plug-chamfer tap drives chips forward ahead of the cutting edge, making it well-suited for through-hole applications. It carries an H3 thread limit and a 3B class of fit, delivering consistent tolerance control in production and repair threading operations. With an overall length of 2.72 inches and a thread length of 0.799 inches, the tool fits standard tapping chucks and holders used in machine shop and field service environments.

This tap is intended for machinists, maintenance technicians, and toolroom professionals working with tough ferrous and exotic alloy materials. The 5/16-24 UNF thread form appears commonly in aerospace, automotive, and industrial equipment assemblies where fine-thread engagement is required for load-bearing fastener joints. It is appropriate for CNC tapping, manual tapping machines, and hand-tap use in through-hole configurations where chip evacuation ahead of the tap is practical.

Key Features

• Spiral point geometry pushes chips forward, reducing chip packing in through-hole applications
• Powdered metal construction provides increased wear resistance versus standard high-speed steel
• Steam oxide coating improves lubricity and reduces galling, especially in stainless steel and high-nickel alloys
• H3 thread limit ensures consistent 3B class of fit across production runs
• Right-hand thread direction, 3 flutes, plug chamfer for standard entry and threading depth control
• Rated for hardened steel, stainless steel, high-nickel alloy, and titanium material applications

Compatibility

Designed for cutting 5/16-24 UNF threads per the OSG 312NI series specification. Suitable for through-hole tapping operations in hardened steel, stainless steel, high-nickel alloy, and titanium workpieces where a 3B class of fit is required.

Installation Notes

This tap should be installed in a tapping chuck or collet holder appropriate for the 0.318-inch shank diameter. Ensure the machine spindle or tapping arm is properly aligned with the pre-drilled hole before engaging the tap to avoid bell-mouthing or tap breakage. Use a cutting fluid or tapping compound rated for the workpiece material, particularly when threading stainless steel or high-nickel alloys. Inspect the tap for wear or chipping between uses, as damaged cutting edges in hard materials can cause rapid tool failure or workpiece damage.