Osg 1010800 Straight Flute Tap 1-72 Unf Bottoming Hss

Product Description

The OSG 1010800 is a straight flute bottoming tap designed for cutting internal threads in pre-drilled holes where full thread depth is required close to the bottom of a blind hole. Manufactured from high-speed steel with a bright/uncoated finish, this tap produces a 1-72 UNF right-hand thread with a 2B class of fit and an H2 thread limit. It features 2 flutes and a bottoming chamfer, making it the right tool when a starting or plug tap has already been run and final thread depth is the goal. Overall length is 1-11/16 inches with a 3/8-inch thread length.

This tap is suited for threading small-diameter holes in a range of ferrous and non-ferrous materials. The 1-72 UNF thread form is commonly found in precision instrument work, electronics enclosures, and light mechanical assemblies where a fine thread pitch is required in a No. 1 screw size. It is appropriate for machine shop, toolroom, and maintenance environments where controlled thread tolerance is critical.

Key Features

• Bottoming chamfer allows threading to the bottom of blind holes after starter or plug tap passes
• High-speed steel construction provides durability across a range of workpiece materials
• Bright/uncoated finish maintains close tolerances without added coating buildup
• 2B class of fit and H2 thread limit suit standard commercial thread tolerance requirements
• Right-hand thread direction compatible with standard tapping equipment and tap wrenches
• 2-flute design aids chip clearance in shallow blind hole applications

Compatibility

Compatible with aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel workpiece materials. Designed as an OEM-style replacement or standard toolroom tap for applications requiring a 1-72 UNF bottoming tap in the OSG Series 102 product line.

Installation Notes

A bottoming tap should only be used after a taper or plug tap has been run to establish the thread form. Secure the workpiece and use appropriate cutting fluid for the material being tapped to extend tool life and improve thread quality. Apply consistent, moderate torque and back off periodically to break chips. Follow shop safety practices and use proper tap holders to avoid breakage in small-diameter taps.