Carmex Thread Mills Solid Carbide - Internal Thread - UN (UNC UNF UNEF UNS) - 7/8 x 9 - MT7The Carmex MT7 solid carbide thread mill delivers precise and efficient internal threading for UN standard fasteners in the 7 8 x 9 size. Machinists and production shops choose this tool when they need reliable thread milling without excessive cost or setup time. Material: Solid carbide construction maintains sharp cutting edges through extended production runs on steel, stainless, and alloy materials. Flute Design: Three to five flutes work together