Osg 1707201 Spiral Point Tap 1/4-20 Unc 3 Flute Plug

Product Description

The OSG 1707201 is a spiral point plug tap designed for threading 1/4-20 UNC internal threads in demanding materials. Manufactured from powdered metal and finished with a steam oxide coating, this tap handles hardened steel, stainless steel, high-nickel alloys, and titanium. The spiral point geometry pushes chips ahead of the cutting action, making it well suited for through-hole applications. With a 3-flute design, an H5 thread limit, and a 2B class of fit, it produces accurate, consistent threads in production and maintenance environments. Licensed machinists, toolroom technicians, and CNC operators are the typical users.

This tap is intended for through-hole threading operations in materials with high hardness or work-hardening tendencies, including hardened steel, stainless steel, high-nickel alloys, and titanium. The plug chamfer provides a gradual lead-in over several threads, which distributes cutting load and reduces tap breakage risk in tough alloys. The right-hand thread direction and standard 1/4-20 UNC profile make it a direct fit for common fastener sizes in both production machining and field repair scenarios. Series 312NI targets nickel-alloy and titanium applications specifically.

Key Features

• Spiral point geometry pushes chips forward for clean through-hole threading
• Powdered metal construction delivers improved wear resistance over standard HSS in abrasive and work-hardening materials
• Steam oxide coating reduces friction and improves lubrication retention during cutting
• H5 thread limit and 2B class of fit for accurate, interchangeable thread production
• Plug chamfer distributes entry load across multiple threads, reducing breakage in hard alloys
• Right-hand, 3-flute design compatible with standard tapping heads and CNC rigid tapping cycles

Compatibility

Rated for use in hardened steel, stainless steel, high-nickel alloys, and titanium. Belongs to OSG Series 312NI, which is specifically formulated for nickel-alloy and titanium material groups. Coolant-through is not supported on this tap.

Installation Notes

Installation is performed by machinists or toolroom technicians using a tapping head, CNC machining center with rigid tapping capability, or manual tap wrench. Always drill the correct tap drill size for 1/4-20 UNC before tapping, and ensure the workpiece is securely fixtured to prevent movement. Use an appropriate 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 after each use to avoid thread quality loss or breakage in the bore.