Harvey Tool 987166-C3 Thread Mill 3/8-24 Internal Altin

Product Description

The HARVEY TOOL 987166-C3 is a solid carbide helical flute thread mill designed for cutting internal 3/8-24 UNF threads. With 4 flutes and an AlTiN coating, it delivers efficient material removal and extended tool life in ferrous and hardened materials. The cutting diameter measures 0.3000 inches and the shank diameter is 0.3750 inches. Length of cut is 1.1250 inches with an overall length of 3.5000 inches. At 24 teeth per inch, this tool is well suited for precision threading operations in CNC machining centers. Coolant-through capability is not included in this configuration.

This thread mill is intended for internal threading applications in production and job-shop environments. It is used in CNC machining operations where helical interpolation is employed to generate 3/8-24 internal threads in a single tool pass or with multiple depth passes. The solid carbide construction and AlTiN coating make it appropriate for use in steel, stainless steel, cast iron, and similar materials. Machinists and CNC operators in aerospace, automotive, and general metalworking sectors will find this tool applicable to both prototype and high-volume threading work.

Key Features

• Solid carbide construction for rigidity and wear resistance in demanding materials
• AlTiN coating provides thermal protection and extends tool life in ferrous applications
• 4-flute helical design for efficient chip evacuation during internal thread milling
• 24 TPI matches 3/8-24 UNF thread specification for precision fitment
• 0.3750-inch shank diameter for direct collet or end mill holder mounting
• 1.1250-inch length of cut accommodates a range of thread depths in typical through and blind-hole applications

Compatibility

Designed for internal 3/8-24 UNF thread milling operations using helical interpolation on CNC machining centers equipped with standard 3/8-inch collet or end mill toolholding systems.

Installation Notes

Installation and operation of this thread mill should be performed by a qualified CNC machinist or tooling specialist familiar with helical interpolation programming. Secure the shank in a precision collet or end mill holder to the manufacturer-recommended runout tolerance before use. Verify spindle speed, feed rate, and helical pitch programming against the tool geometry before engaging the workpiece. Always ensure the machine is in a safe, stopped state when loading or unloading the tool.