A coupling nut, also known as extension nut, is a threaded fastener for joining two male threads, most commonly a threaded rod, but also pipes. The outside of the fastener is usually a hex so a wrench can hold it. Variations include reducing coupling nuts, for joining two different size threads; sight hole coupling nuts, which have a sight hole for observing the amount of engagement; and coupling nuts with left-handed threads.
Ningbo Weifeng Fastener Co., Ltd., established in the year 2003, is a global industry and trade combined company. Our company is specialized in developing, manufacturing, trading and providing services for fasteners and hardware tools.