Osg 1430401 Spiral Flute Tap 5/16-18 Unc Hss

Product Description

The OSG 1430401 is a spiral flute tap designed to cut internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel with a steam oxide coating, it produces 5/16-18 UNC right-hand threads to a 3B class of fit with H3 thread limit. The plug chamfer provides a gradual thread lead-in suited for through-hole tapping applications. With a 50-degree helix angle, the spiral flute geometry evacuates chips back out of the hole, making this tap effective in blind-hole and through-hole scenarios where chip packing is a concern. Licensed machinists, toolroom techs, and maintenance professionals install this tap in standard tap handles, T-handle wrenches, or CNC rigid tapping setups.

The OSG 1430401 is suited for production and maintenance tapping in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. It fits residential and commercial maintenance shops, fabrication facilities, and field service environments where 5/16-18 UNC fastener threads are common. The Series 107 designation identifies this as part of OSG's standard spiral flute tap line. With an overall length of 2.719 inches and a shank diameter of 0.318 inches, it fits standard tap wrench and machine collet holders sized for this shank.

Key Features

• 5/16-18 UNC thread form, 3B class of fit, H3 thread limit for consistent tolerance control
• 50-degree helix angle spiral flute design evacuates chips away from the cutting zone
• Plug chamfer for gradual thread engagement in through-hole applications
• Steam oxide coating reduces friction and provides light corrosion resistance
• High-speed steel construction suitable for aluminum, cast iron, and carbon steel grades
• Right-hand thread direction, no coolant-through - compatible with standard tapping setups

Compatibility

Designed for tapping 5/16-18 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Fits standard tap handles and machine tool holders sized for a 0.318-inch shank diameter.

Installation Notes

Machinists and maintenance technicians install this tap using a T-handle tap wrench, adjustable tap wrench, or rigid CNC tapping setup. Ensure the workpiece is securely fixtured and the tap is started perpendicular to the hole to avoid thread misalignment or tap breakage. Use an appropriate cutting fluid for the workpiece material to extend tap life and improve thread finish. Inspect the tap for wear or chipping before each use and replace if cutting edges show deterioration.