Imperial hex nut adopts inch thread sizes, divided into UNC coarse thread and UNF fine thread. Matched with inch bolts only, cannot interchange with metric nuts.

Materials: Carbon steel, A2(304)/A4(316) stainless steel. Surface finish: black oxide, blue-white zinc, yellow zinc, hot-dip galvanized. Common sizes: 1/4", 5/16", 3/8", 1/2", 5/8", 3/4". Widely used for imported machinery maintenance, marine equipment, old-type machines and overseas engineering projects.