Osg 1201400 Spiral Point Tap 4-40 Unc 2 Flute Hss

Product Description

The OSG 1201400 is a spiral point tap designed for threading 4-40 UNC holes in a wide range of metals. It features a plug chamfer style, 2 flutes, and is manufactured from high-speed steel with a bright finish. The spiral point geometry pushes chips forward ahead of the cut, making it well-suited for through-hole tapping applications. At 1.875 inches overall length with a thread length of 0.3125 inches and a shank diameter of 0.141 inches, this tap fits standard tap handles and machine tap holders. The H1 thread limit designation indicates a tight tolerance class, appropriate for close-fit thread requirements. Installed by machinists, toolmakers, and maintenance technicians across production and repair applications.

This tap is intended for use in through-hole tapping operations on a broad range of metals including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. It is suited for both hand tapping and machine tapping setups where the 4-40 UNC thread form is required. The plug chamfer, with its gradual thread lead-in, is the most common style for general-purpose threading work in production or field maintenance environments.

Key Features

• Spiral point geometry advances chips forward for clean through-hole threading
• High-speed steel construction provides durability across a wide range of workpiece materials
• Plug chamfer style offers a balanced lead-in suitable for most general-purpose applications
• H1 thread limit for close-tolerance 4-40 UNC thread production
• Right-hand thread direction, standard for the vast majority of fastener applications
• Bright finish with no coolant-through requirement simplifies tooling setup

Compatibility

Designed as a standard 4-40 UNC spiral point plug tap compatible with conventional tap handles, tapping heads, and CNC machine tap holders that accept the corresponding shank diameter.

Installation Notes

This tap is installed by machinists or maintenance technicians using a standard tap handle or machine tapping setup. Ensure the workpiece is securely fixtured and the tap is started square to the hole to avoid thread damage or tap breakage. Apply appropriate cutting fluid for the workpiece material to extend tap life. At the 4-40 size, taps are particularly susceptible to breakage under side load or misalignment, so careful alignment is critical.