Osg 2103800 Spiral Point Extension Tap 3/8-16 Unc Hss

Product Description

The OSG 2103800 is a spiral point plug tap designed for right-hand threading in a range of ferrous and non-ferrous materials. Built from high-speed steel with a bright uncoated finish, this extension tap features three flutes and an H3 thread limit, producing 3/8-16 UNC threads to a 3B class of fit. The 4-inch overall length with a reduced shank and extended neck length makes it suitable for threading in recessed or hard-to-reach locations where a standard-length tap would not reach. It is used by machinists, tool-and-die makers, and maintenance technicians working in production or repair environments.

This tap is suited for through-hole threading applications in aluminum, carbon steel, and cast iron, as well as hardened steel. The spiral point design pushes chips forward ahead of the tap, keeping the flutes clear and reducing the risk of tap breakage in through-hole work. The plug chamfer provides a gradual lead-in, making it appropriate for most standard through-hole threading jobs. It fits standard tap handles and extension holders sized for a 0.381-inch shank diameter.

Key Features

• Spiral point design pushes chips forward, reducing clogging in through-hole applications
• High-speed steel construction handles aluminum, carbon steel, cast iron, and hardened steel
• Reduced shank and 1.413-inch neck length extends reach into deep or recessed bores
• H3 thread limit and 3B class of fit meet standard UNC tolerance requirements
• Bright uncoated finish suitable for use with cutting fluid in general-purpose threading
• Right-hand flute direction and right-hand thread direction for standard tapping operations

Compatibility

Designed for use in standard tap handles and extension holders accepting a 0.381-inch reduced shank. Compatible with threading applications in aluminum, carbon steel, cast iron, and hardened steel requiring 3/8-16 UNC internal threads to a 3B class of fit.

Installation Notes

This tap should be installed by a qualified machinist or maintenance technician. Power down and secure the workpiece before beginning any tapping operation. Apply appropriate cutting fluid for the material being threaded to extend tool life and improve thread quality. Do not reverse a spiral point tap mid-thread in a through-hole without first clearing chips, as this can cause tap breakage.