Cleveland C59122 Extension Tap 5/16-24 Unf Spiral Point Hss

Product Description

The CLEVELAND C59122 is a spiral point plug extension tap designed for cutting right-hand internal threads in through-hole applications. It threads to a 5/16-24 UNF specification with an H3 thread limit, providing a controlled fit tolerance suitable for most standard fastener assemblies. Built from high speed steel (HSS) with a bright, uncoated finish, this tap delivers solid performance across a range of ferrous and non-ferrous materials. The overall length of 6 inches gives machinists and toolmakers the reach needed for deep setups or fixtures where a standard-length tap cannot access the workpiece. It is sold individually and suited for manual or machine tapping operations.

This tap is used in production machining, tool and die work, and maintenance repair operations wherever a 5/16-24 UNF thread is required in a through-hole. The spiral point geometry pushes chips forward ahead of the cutting edge, making it well suited for through-hole tapping on CNC machining centers, drill presses, and tapping heads. The plug chamfer provides a gradual thread lead-in, balancing cutting efficiency with tool life in moderate-depth through-hole applications.

Key Features

• 5/16-24 UNF thread size with H3 thread limit for controlled fit tolerance
• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• Plug chamfer for balanced lead-in and cutting performance
• 6-inch overall length provides extended reach for deep fixtures and setups
• High speed steel construction for durability across common workpiece materials
• Right-hand flute direction, 3 flutes, bright uncoated finish

Compatibility

Designed for through-hole tapping applications requiring a 5/16-24 UNF thread with a 2B class of fit. Suitable for use with standard tapping heads, CNC rigid tapping setups, and hand-tapping operations on compatible toolholders accepting the tap shank.

Installation Notes

This tap should be installed by a machinist or toolroom professional familiar with tapping speeds, feeds, and cutting fluid requirements for the workpiece material. Always secure the workpiece and verify spindle alignment before beginning the tapping cycle. Use an appropriate cutting or tapping fluid to extend tool life and improve thread finish. Inspect the tap for wear or chipping before each use and replace if cutting edges show damage.