Osg 1431200 Spiral Flute Tap 7/16-14 Unc Plug Hss

Product Description

The OSG 1431200 is a spiral flute plug tap designed for cutting internal threads in a wide range of ferrous and non-ferrous metals. Built from high-speed steel with a bright uncoated finish, it cuts a 7/16-14 UNC right-hand thread and features three right-hand spiral flutes with a 50-degree helix angle. The plug chamfer provides a gradual lead-in that suits through-hole and blind-hole applications alike. Overall length is 3.156 inches with a shank diameter of 0.323 inches. The H3 thread limit tolerance makes it appropriate for standard class-3B fit internal thread applications encountered in general machining and maintenance work.

This tap is suited for threading operations in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The steep 50-degree helix angle efficiently evacuates chips up and out of the hole, reducing clogging in ductile materials. It is commonly used in machine shop environments, field maintenance, and manufacturing production where reliable UNC thread formation is required. Coolant-through capability is not available on this model, so flood or mist coolant applied externally is the standard approach.

Key Features

• 7/16-14 UNC right-hand thread, H3 thread limit for class-3B fit
• 50-degree right-hand spiral helix for efficient chip evacuation in ductile materials
• High-speed steel construction for durability across ferrous and non-ferrous workpieces
• Bright uncoated finish - no additional coating buildup affecting tolerance
• Plug chamfer for versatile use in through-holes and blind holes
• Compact 3.156-inch overall length suitable for standard tap holders and machine spindles

Compatibility

Designed for use in standard 7/16-14 UNC tapping applications across aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpiece materials. Part of OSG Series 107.

Installation Notes

This tap is installed by a machinist or maintenance technician using a standard tap wrench, tapping head, or CNC machine spindle. Always secure the workpiece and ensure the tap is aligned perpendicular to the drilled hole before starting the thread. Apply appropriate cutting fluid for the workpiece material to reduce friction and extend tool life. Inspect the tap for wear or chipping before each use - a damaged tap can seize in the hole or produce out-of-tolerance threads.