The fasteners commonly used in China are made of cast iron, and their mechanical properties are to comply with the requirements of "Steel Pipe Scaffolding Fasteners" (GB15831-2006). The material is not lower than KT330-08. There are three kinds of fasteners: right angle fasteners, docking fasteners, rotating fasteners. Packed in woven bags, each pack is 25 pieces. Each weight should be 1.1KG (with bolts and nuts). In general, anti-rust treatment is performed in the form of a bluish anti-rust paint. Used with a shelf tube. The general fastener product production and purchase ratio is 8:1:1. That is to say, the ratio is 80% in right angles, 10% in butt joints and 10% in rotations.