Osg 1046200 Bottoming Tap 3/8-16 Unc 3 Flute Hss

Product Description

The OSG 1046200 is a straight flute bottoming tap designed for threading blind holes where threads must extend as close to the bottom as possible. Manufactured from high-speed steel with a bright uncoated finish, this tap cuts a 3/8-16 UNC right-hand thread. It runs 3 flutes with an H1 thread limit, making it well suited for applications that require close tolerance control. Overall length is 2-15/16 inches with a thread length of 1-1/4 inches. A bottoming chamfer allows full thread engagement near the base of the hole, reducing the unusable thread-free zone at the bottom of a blind bore.

This tap is intended for use in machine shop, maintenance, and production tapping operations across a range of ferrous and non-ferrous materials. It performs in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. It is appropriate for use in manual tapping handles, drill press setups, and CNC or turret tap holders where a straight flute geometry is preferred. The H1 thread limit suits general-purpose UNC threading where standard fit class is acceptable.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 3 straight flutes for chip control in through and blind hole applications
• High-speed steel construction provides hardness and wear resistance across a broad material range
• H1 thread limit for controlled thread tolerance
• Bright uncoated finish suitable for use with standard cutting fluids
• No coolant-through requirement simplifies setup in standard tapping equipment

Compatibility

Designed as an OEM-style replacement or direct-use tap for standard 3/8-16 UNC bottoming tap applications in production and maintenance threading operations.

Installation Notes

This tap is installed and driven by a licensed machinist or qualified tradesperson using a tap wrench, tapping head, or CNC tool holder sized to the shank diameter of 0.381 inches. Always drill the correct tap drill diameter for 3/8-16 UNC threads before tapping and ensure the workpiece is securely fixtured. Apply an appropriate cutting fluid for the material being tapped to extend tap life and improve thread finish. For blind hole applications, verify hole depth allows sufficient clearance beyond the required thread depth before driving the bottoming tap to full depth.