Scientific Cutting Tools TM170-20HA Thread Mill 1/4-20 Unc

Product Description

The SCIENTIFIC CUTTING TOOLS TM170-20HA is a helical flute thread mill designed for cutting 1/4-20 UNC threads in both internal and external applications. Manufactured from submicron-grade solid carbide and finished with an AlTiN+ coating, this tool delivers wear resistance and thermal stability in demanding milling operations. The 3-flute, right-hand configuration with a 0.1700-inch cutting diameter and 0.5200-inch length of cut makes it well suited for precise thread forms in a range of workpiece materials. Machinists and tooling specialists working in production or job-shop environments rely on this class of thread mill for consistent, repeatable thread geometry.

This thread mill is used in CNC machining centers for generating 1/4-20 UNC threads without the risk of tap breakage in difficult materials. Its internal and external threading capability allows a single tool to handle both bore and external-feature applications. The 2.5000-inch overall length and 1/4-inch shank diameter suit standard collet and end mill holders found on vertical and horizontal machining centers. It is a practical choice for aerospace, automotive, mold and die, and general precision machining work where carbide thread mills are specified over taps.

Key Features

• Cuts 1/4-20 UNC threads at 20 teeth per inch, internal and external in a single tool
• Submicron-grade solid carbide blank for enhanced rigidity and tool life
• AlTiN+ coating improves heat resistance and reduces built-up edge in ferrous and exotic alloys
• 3-flute, right-hand helical geometry for smooth chip evacuation during thread milling cycles
• No coolant-through design simplifies setup for standard flood or mist coolant delivery
• 0.5200-inch length of cut accommodates typical thread depth requirements for 1/4-20 fastener holes

Compatibility

Designed as an OEM-style thread mill for CNC machining centers using standard 1/4-inch shank collet or end mill tool holders capable of executing helical interpolation cycles for 1/4-20 UNC thread forms.

Installation Notes

Thread milling requires a CNC control capable of helical interpolation; verify the machine program uses the correct thread mill cycle before running. Secure the 1/4-inch shank with a properly torqued collet or end mill holder to minimize runout, which directly affects thread accuracy. Inspect the cutting edges before use and replace the tool at the first sign of chipping or coating wear to prevent thread-form errors. Follow applicable shop safety practices when handling carbide tooling.