Osg 2986601 Spiral Flute Tap 6-40 Unf Bottoming Hss

Product Description

The OSG 2986601 is a spiral flute bottoming tap designed for cutting internal 6-40 UNF threads in blind holes. Built from high-speed steel with a steam oxide coating, it runs two right-hand flutes at a 50-degree helix angle to evacuate chips efficiently toward the shank. The bottoming chamfer geometry allows threading close to the bottom of a blind hole, making it the right choice when thread depth is critical. Overall length is 2 inches with a thread length of 0.37 inches. This tap is suited for machinists, tool-and-die makers, and maintenance technicians working in precision thread repair or production tapping applications.

The 2986601 is rated for use in aluminum and carbon steel. The 2B class of fit delivers a standard commercial tolerance suitable for the majority of fastener and assembly applications. Coolant-through capability is not included, so it is best run with surface-applied cutting fluid or tapping compound. The right-hand thread direction and right-hand flute orientation are standard for conventional tapping with a tap wrench, drill press, or CNC tapping cycle.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 50-degree helix angle promotes efficient chip evacuation in the spiral flute design
• High-speed steel construction provides durability across aluminum and carbon steel workpieces
• Steam oxide coating reduces friction and provides mild corrosion resistance
• 2B class of fit meets standard commercial thread tolerance requirements
• Compact 2-inch overall length fits most standard tap holders and collets

Compatibility

Designed as an OEM-style replacement tap for 6-40 UNF bottoming applications in standard tap holders accepting a 0.141-inch shank diameter with a 0.11-inch square drive.

Installation Notes

This tap should be installed and operated by machinists or maintenance technicians familiar with thread-cutting procedures. Always secure the workpiece firmly and use appropriate cutting fluid for the material being tapped. Ensure the tap is aligned perpendicular to the workpiece surface before beginning the cut to avoid tap breakage or cross-threading. When using with power equipment, confirm the spindle speed and feed rate are appropriate for the tap size and workpiece material before engaging.