Osg 2930300 Spiral Flute Tap 1/4-28 Unf 3 Flute

Product Description

The OSG 2930300 is a spiral flute tap designed for cutting internal 1/4-28 UNF right-hand threads in a range of ferrous materials. Built from vanadium high-speed steel with a bright uncoated finish, this tap features a 45-degree helix angle that promotes efficient chip evacuation in blind-hole applications. The modified bottoming chamfer allows threading close to the bottom of a hole while still providing enough lead-in to start cleanly. It is sized at 2.5 inches overall length with a 0.255-inch shank diameter. Machinists, tool-and-die makers, and maintenance technicians working on precision assemblies are the typical users.

This tap is suited for production and maintenance threading operations in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. The spiral flute design is especially effective in blind-hole setups where chip packing is a concern. It carries an H2 thread limit, making it appropriate for standard UNF tolerance fits commonly required in hydraulic fittings, fastener repairs, and precision mechanical assemblies.

Key Features

• 45-degree helix angle for positive chip ejection in blind holes
• Modified bottoming chamfer allows threading close to hole bottom
• Vanadium high-speed steel construction for wear resistance across ferrous materials
• H2 thread limit for consistent UNF tolerance control
• Bright uncoated finish suitable for use with standard cutting fluids
• Right-hand flute direction and right-hand thread for standard CW tapping

Compatibility

Designed for cutting 1/4-28 UNF internal threads in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel workpieces. Coolant-through is not supported on this tap.

Installation Notes

Install in a tapping chuck or rigid tap holder appropriate for the shank diameter. Always power down or de-energize CNC equipment and clear the work area before tool changes. Use an appropriate cutting fluid or tapping compound for the workpiece material to extend tool life and improve thread finish. Follow shop-standard speeds and feeds for high-speed steel taps; do not exceed the tap's rated hardness range for the workpiece material.