M12 1.75, M12 1.5, M12 1.25, M10 1.5, M10 1.25, M8 1.25, M6 1.0. To use a thread chaser, simply fasten it on a threaded hole or bolt as you would with regular bolts or nuts. Thread chaser set is made of the highest quality carbon steel materials, with strong strength and maximum durability.