The B18/BN830 is a type of threaded fastener manufactured by Bossard. It is a metric thread, T-head bolt and has a cylindrical body. It features a flat head with a chamfered edge for easy installation and removal. It has an O-ring at the head of the bolt, which creates a water and air tight seal against the mating surface. The bolt is made from high-grade steel, which gives it great strength and durability. It is commonly used in various applications such as industrial machinery, bicycle components, automotive components, furniture, and more.