Milwaukee 4-40 NC SAE 1" Hex Threading Die is the tool for creating or repairing precise external threads. Precision machined and built to last, this Hex Die features long-lasting laser-etched sizing for clear markings and a protective Black Oxide coating that provides excellent corrosion resistance. The 1” Hex shape is compatible with the MILWAUKEE® Hex-LOK™ 2-in-1 Threading Handle, as well as all standard 1” Hex Die stocks. Engineered for durability, this Hex Die is designed to cut threads in common metal applications such as brass, aluminum, and mild steel. For results, it is to use cutting fluid during operation to ensure smooth and accurate threading. Model Number: 49-57-5308