Comparison of Loosening Characteristics of 3/8 BSW Threaded Fasteners under Accelerated Vibratory Condition

Nuts and bolts are widely used fastening elements in industrial and household applications. They offer a good amount of tightening load to remain in the fastened element and also cause easy assembly and disassembly. However, they are also subject to loosening under transverse vibration. Therefore, fasteners need be properly selected according to their applications or else they may cause fatal mishaps by their loosening. In the present work, an effort has been made to evaluate a comparative study of loosening tendency of various threaded fasteners. Tests have been carried out on 3/8 BSW Stainless Steel and High Tension Steel Bolts fitted with different nuts and washers. Tests were carried out on an indigenously made testing rig. The decrease in clamping force has been recorded at regular intervals. Then a comparative study of the loosening tendency of the threaded fasteners is made to find out one having good resistance to loosening under hostile vibration condition.