It is called spring U bolt. It is used in automotive industry,agricultural equipments. U-bolt has one twist, two twist, three twist types. These U-bolts are producing thread(pitch) diameter or major diameter. In major diameter which is U-bolts also has hot reduced types. It has 8.8, 10.9 and 12.9 quality and coating with ZnCr+3, phosphate and geomet.

ASB U-BOLT FORM