Scientific Cutting Tools TMI620-8HA Thread Mill 1-8 Unc

Product Description

The SCIENTIFIC CUTTING TOOLS TMI620-8HA is a helical flute thread mill designed for cutting internal UNC threads in a single helical interpolation pass. Built from submicron-grade solid carbide and finished with an AlTiN+ coating, this tool delivers consistent thread form in ferrous and non-ferrous materials at elevated cutting speeds. With a 0.6200-inch cutting diameter and 1.5500-inch length of cut, it handles the full depth requirements of standard 1-8 UNC internal threads. The four-flute, right-hand helical geometry reduces radial cutting forces and produces a clean finish in through-hole and blind-hole applications. Machinists and toolroom technicians working on CNC machining centers use this tool as a direct replacement for traditional single-point thread boring or tapping operations.

This thread mill is configured for 1-8 UNC internal threads with a minimum nominal diameter of 1.0000 inch, making it appropriate for structural fastener holes, fixture components, and mechanical assemblies requiring coarse-pitch unified thread forms. The long-reach thread mill design accommodates deeper bore access where standard-length tools cannot reach. It is suited for use in steel, stainless steel, cast iron, aluminum, and similar materials on three- and four-axis CNC machining centers with helical interpolation capability. A 5/8-inch shank diameter provides rigid coupling to standard ER or end-mill-style toolholders.

Key Features

• Submicron-grade solid carbide substrate for high wear resistance and dimensional stability
• AlTiN+ coating extends tool life in ferrous materials and supports dry or minimum-quantity lubrication cutting
• 4-flute right-hand helical geometry reduces cutting forces and improves thread surface finish
• Long-reach thread mill configuration for deep-bore or restricted-access thread milling operations
• Single tool cuts the complete 1-8 UNC internal thread form in one helical interpolation pass
• No coolant-through - compatible with flood coolant applied externally at the machine spindle

Compatibility

Designed for CNC machining centers capable of helical interpolation. Cuts 1-8 UNC internal threads with a minimum nominal diameter of 1.0000 inch. Accepts standard 5/8-inch bore toolholders.

Installation Notes

This tool must be run on a CNC machining center programmed for helical interpolation - it is not a tap and cannot be used in a tapping head or manual drill press. Secure the 5/8-inch shank in a properly sized and balanced toolholder and verify runout before cutting. Program feed rate, spindle speed, and helical pitch according to the material being machined and the manufacturer's cutting data recommendations. Inspect the cutting edges for chipping before each use, as carbide thread mills are sensitive to interrupted cuts and re-entry into pre-existing threads.