Osg 1432900 Spiral Flute Tap 5/8-11 Unc Bottoming Hss

Product Description

The OSG 1432900 is a spiral flute bottoming tap designed for cutting 5/8-11 UNC right-hand internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel with a bright uncoated finish, this tap features 4 flutes with a 50-degree helix angle that efficiently evacuates chips upward during the tapping operation. The bottoming chamfer allows threading close to the bottom of a blind hole, making it the correct choice when full thread depth near the bottom of a bore is required. It carries an H3 thread limit and a 3B class of fit, suitable for general-purpose industrial threading work. Overall length is 3.813 inches and the part weighs 0.191 pounds.

This tap is intended for use in machining and metalworking environments where blind-hole threading is common. The high helix spiral flute design makes it well suited for softer, stringy materials where chip clearance is critical, as well as harder steels where controlled chip flow improves tool life. Applicable materials include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. It is typically run on CNC machining centers, manual knee mills, or drill presses equipped with a tapping head. The 3B class of fit is standard for most general fastener applications.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• 50-degree right-hand helix flute for efficient upward chip evacuation
• H3 thread limit with 3B class of fit for general-purpose industrial threading
• High-speed steel construction handles aluminum, cast iron, and carbon steels
• Bright uncoated finish - no coating buildup issues when regrinding
• Coolant-through: No - suitable for flood or manual lubrication

Compatibility

Designed for cutting 5/8-11 UNC right-hand internal threads. Compatible with standard 5/8-11 UNC tapping applications across aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces.

Installation Notes

This tap is installed and operated by a qualified machinist or tooling professional. Before tapping, confirm the correct drill size for a 5/8-11 UNC thread has been used to prepare the pilot hole. Use an appropriate cutting fluid or tapping compound for the workpiece material to extend tool life and improve thread quality. Ensure the workpiece is securely fixtured and the tap is held in a proper tap holder to maintain axial alignment throughout the cut.