Osg 1206401 Spiral Point Tap 4-40 Unc Plug Hss

Product Description

The OSG 1206401 is a spiral point tap designed for cutting 4-40 UNC threads in through-hole applications. It features a plug chamfer and a 2-flute spiral point geometry that pushes chips forward ahead of the cut, keeping the flutes clear and reducing the risk of chip-related tap breakage. Built from high-speed steel with a steam oxide coating, it is suited for use in a broad range of ferrous and non-ferrous materials. The H2 thread limit provides a controlled oversize tolerance appropriate for standard 2B and 3B class-of-fit thread requirements. Licensed machinists and tooling technicians are the primary users of this tap in production and maintenance environments.

This tap is used in applications where through-hole tapping is required at the 4-40 UNC thread size. The spiral point design makes it well-suited for moderate-volume production work where chip evacuation in blind pockets would otherwise be a concern. Rated for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel, it covers a wide cross-section of material types encountered in general machining, HVAC equipment assembly, electrical enclosure fabrication, and maintenance repair operations.

Key Features

• Spiral point geometry pushes chips forward for clean through-hole tapping
• 2-flute configuration suitable for a wide range of workpiece materials
• Plug chamfer provides standard entry taper for general-purpose threading
• H2 thread limit for controlled 2B and 3B class-of-fit tolerance
• Steam oxide coating improves lubricity and provides mild corrosion resistance
• High-speed steel construction for durability across ferrous and non-ferrous applications

Compatibility

Designed for through-hole tapping of 4-40 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces. Right-hand threading only. Not intended for coolant-through tooling setups.

Installation Notes

Use with a compatible tap wrench, tapping head, or CNC rigid tapping setup rated for the 4-40 thread size. Ensure the workpiece is securely fixtured and the tap is aligned perpendicular to the drilled hole before engagement. Apply appropriate cutting fluid or tapping compound for the workpiece material to extend tool life. Replace worn taps promptly to avoid thread quality degradation and tap breakage.