Electro-zinc plated coupling nut in accordance with the DIN 6334 standard is a reliable and durable nut used, among other things, to connect two externally threaded fasteners. It has an electro-zinc plated surface treatment that gives limited corrosion resistance and protection against rust, and it is therefore best suited for indoor use. It is ideal for use in construction, machine building and other applications where threaded fasteners need to be extended or joined.