Scientific Cutting Tools TM.400-20 Thread Mill 1/2-20 Unf

Product Description

The SCIENTIFIC CUTTING TOOLS TM.400-20 is a straight flute thread mill designed for cutting internal 1/2-20 UNF threads in a CNC machining environment. Built from submicron-grade solid carbide, this tool delivers the rigidity and edge retention required for threading ferrous and non-ferrous workpiece materials. It runs 4 flutes with a 0.4-inch cutting diameter and a 1.07-inch length of cut, covering full thread depth in a single helical interpolation pass. The bright finish reduces friction without the added cost of a specialized coating. Machinists and CNC programmers working in job shop, aerospace, and general manufacturing environments rely on this tool for consistent thread form and tool life.

This thread mill is suited for internal 1/2-20 UNF applications where a standard tap would present risks from tool breakage, poor chip evacuation, or limited access. Straight flute geometry performs well in shorter-chipping materials. With a 1/2-inch shank diameter and 3.5-inch overall length, it fits standard ER or end mill holders and accommodates the reach requirements common in production and prototype machining. It is installed and operated by machinists running 3-axis or 5-axis CNC machining centers with helical interpolation capability.

Key Features

• Submicron-grade solid carbide construction for superior hardness and edge retention
• 4 straight flutes with 0.4-inch cutting diameter for 1/2-20 UNF internal threads
• 1.07-inch length of cut accommodates full thread depth in one helical pass
• Bright finish reduces friction without adding coating cost
• 1/2-inch shank diameter fits standard ER collet and end mill holders
• 3.5-inch overall length provides reach for recessed or deep-bore thread applications

Compatibility

Designed for cutting internal 1/2-20 UNF threads on CNC machining centers with helical interpolation capability. Fits standard 1/2-inch ER collet chucks and end mill holders.

Installation Notes

Thread mills require a CNC machining center programmed for helical interpolation. Secure the tool in a balanced, properly torqued holder to minimize runout before cutting. Verify spindle speed and feed rate in the CAM program before first cut, and confirm the coolant strategy matches the workpiece material. No through-coolant is available on this tool, so external coolant or air blast is required for chip clearing.