Scientific Cutting Tools SPTM138L Thread Mill 3 Flute Carbide

Product Description

The SCIENTIFIC CUTTING TOOLS SPTM138L is a single profile thread mill designed for cutting both internal and external threads in the 10-24 to 10-56 range, covering 24 to 56 TPI. Built from submicron-grade solid carbide, this tool delivers precise thread geometry on ferrous and non-ferrous materials in a single helical pass. With a 0.138-inch cutting diameter and a 0.075-inch neck diameter, it is optimized for threading small-diameter features where rigidity and accuracy are critical. The bright, uncoated finish makes edge condition easy to inspect between cuts. Machinists running CNC machining centers will find this tool well-suited to high-precision production and prototype threading operations.

This thread mill is suited for shop environments requiring flexibility across multiple thread pitches without a dedicated tap for each size. The single-profile design allows one tool to produce any thread pitch within its TPI range by adjusting the helical interpolation pitch in the CNC program. It is used in general machining, toolroom work, medical component production, and aerospace applications where thread form accuracy and tool life consistency are priorities. The 3/16-inch shank fits standard collet chucks and end mill holders commonly found on vertical and horizontal machining centers.

Key Features

• Covers 10-24 to 10-56 thread range (24 to 56 TPI) with a single tool
• Cuts both internal and external threads via helical interpolation
• Submicron-grade solid carbide construction for wear resistance and edge stability
• 3 flute design balances chip evacuation and cutting stability in small-diameter threading
• 0.075-inch neck diameter enables reach into tight bore geometries
• Bright, uncoated finish - no coating buildup risk on cutting edge

Compatibility

Designed for use in CNC machining centers capable of helical interpolation; accepts standard 3/16-inch collet chucks and end mill holders. Compatible with any thread profile in the 10-24 to 10-56 range on internal and external features.

Installation Notes

Thread milling requires a CNC control with helical interpolation capability - confirm program compatibility before setup. Secure the 3/16-inch shank in a clean, properly sized collet or end mill holder and verify runout before cutting. Spindle speed, feed rate, and helical pitch must be calculated for the specific thread size and workpiece material. Inspect the cutting edge under magnification before use, as carbide tools are sensitive to chipping from improper handling or storage.