Osg 1181400 Straight Flute Tap 3/8-16 Unc Bottoming Hss

Product Description

The OSG 1181400 is a straight flute bottoming tap designed to cut 3/8-16 UNC internal threads in blind and through holes where full thread depth is required close to the bottom. Made from high-speed steel with a bright, uncoated finish, it runs 3 flutes and is ground to an H5 thread limit with a 2B class of fit. Overall length is 2-15/16 inches with a 1-1/4 inch thread length, making it a standard-length tap suited to hand tapping and machine tapping setups. Machinists, maintenance technicians, and tool-and-die professionals specify this tap for production and repair threading operations.

This tap is intended for threading ferrous and non-ferrous materials including low-carbon steel, medium-carbon steel, high-carbon steel, cast iron, aluminum, and cast aluminum. The bottoming chamfer configuration - typically 1 to 2 threads of lead - allows the tap to thread as close to the bottom of a blind hole as possible after a taper or plug tap has started the thread. It belongs to OSG Series 103, a straight flute line suited to short-chipping materials where flute geometry assists chip control without spiral extraction.

Key Features

• Bottoming chamfer for maximum thread depth in blind holes
• 3 straight flutes for use in short-chipping materials such as cast iron and aluminum
• H5 thread limit provides a controlled oversize tolerance appropriate for 2B class fits
• High-speed steel construction delivers durability across a wide range of workpiece materials
• Bright, uncoated finish compatible with standard cutting fluids and oils
• Right-hand thread direction, no coolant-through feature

Compatibility

Designed as a standard replacement or production tap for 3/8-16 UNC threading applications in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces.

Installation Notes

This tap should be installed and operated by a qualified machinist or maintenance technician following standard threading practices. Always secure the workpiece and use appropriate cutting fluid or tapping oil for the material being threaded. Power down or de-energize any machine tool before changing tooling. Follow applicable shop safety standards and manufacturer torque guidelines for the tapping equipment in use.