Osg 1748001 Spiral Flute Tap 4-40 Unc 2 Flute

Product Description

The OSG 1748001 is a spiral flute tap designed for threading 4-40 UNC internal threads in metalworking and machining applications. Built from vanadium high-speed steel with a steam oxide coating, it delivers resistance to heat buildup and wear during tapping operations. The modified bottoming chamfer allows threading close to the bottom of blind holes. With a 45-degree helix angle and 2 right-hand spiral flutes, chips are efficiently evacuated up and out of the hole, reducing the risk of packing and tap breakage. This tap is suited for use in manual and machine tapping setups where precision thread fitment is required.

This tap is rated for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. The H3 thread limit provides a tighter tolerance class suitable for standard UNC fit requirements. With an overall length of 1-7/8 inches and a thread length of approximately 0.197 inches, it fits standard tapping chucks and holders used in drill presses, CNC machining centers, and hand tapping fixtures. It is commonly installed by machinists, tool and die makers, and maintenance technicians working on precision assemblies.

Key Features

• 4-40 UNC thread size with 40 threads per inch for fine fastener applications
• Modified bottoming chamfer for threading near the bottom of blind holes
• 45-degree right-hand spiral flutes for upward chip evacuation
• Vanadium high-speed steel construction for durability in ferrous metals
• Steam oxide coating reduces friction and improves corrosion resistance
• H3 thread limit for consistent tolerance control in standard UNC fits

Compatibility

Rated for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Designed as an OEM-style replacement or direct-use spiral flute tap for standard 4-40 UNC tapping operations in machining and maintenance environments.

Installation Notes

Installation should be performed by qualified machinists or maintenance technicians familiar with tapping procedures and cutting tool safety. Always ensure the workpiece is securely fixtured and the tap is properly aligned before beginning the threading operation. Use appropriate cutting fluid for the workpiece material to extend tool life and improve thread quality. Inspect the tap for wear or chipping before each use and replace if damage is detected.