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Washers Controlling loosening of Full Threaded Bolted Joints

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Washers Controlling loosening of Full Threaded Bolted Joints

Bolted joints are used for fastening components together in the industry, aeronautics and in railways. These joints may get loose with time and if not attended timely may result in catastrophic failure also. The purpose of this study was to examine the effect of tightening torque on loosening. For this purpose tests were conducted using three different tightening torque values, in the vicinity of rated torque. Washers of different types are used in bolted joint, with an understanding that they prevent or retard loosening. This study also attempts to examine the role of two types of most commonly used washers: the plain washer and the spring washer. Trials were also performed on joint without any washer, for the sake of comparison of loosening performance of the joint. The results of this experimental study are shown in terms of starting point of loosening of joint and rate of loosening of the joint. Various combinations of washers for three values of tightening torque are considered in the experimental study. The results are useful in understanding the role of type of washer in prevention of loosening of the bolted joint.


Bolted joints are used to connect parts or plates and can withstand huge amount of pressure and torque without any damage to the parts being tightened. This is a result of the forces or preload given at work between the nut-bolt and connected surfaces. Bolted joints are used in many places in engineering applications such as automobiles, aeronautics and railways, because of their easy installation and removal for maintenance whenever required as well as due to their low cost in comparison to other types of joints. Forces of the application produce loads that exceed the clamp load, causing the joint to loosen over time. The loosening in bolted joint is a problem; because with the loosened or damaged bolts serious injury may occur to person operating the machine. It is a serious problem and should be solved anyhow. By understanding of loosening, caused by dynamic load such failures can be avoided.



2nd International Conference on Innovations in Automation and Mechatronics Engineering, ICIAME 2014

Shriram Dravid
Research Scholar Bhagwant University,Ajmer,(Raj,and Asst Professor SVCE,Indore,(M.P.),India

Kartikeya Tripathib
Professor,Shri GS Institute of Technology and Science,Indore,(M.P.),India

Manoj Choukseyca
Asst. Professor,Shri GS Institute of Technology and Science,Indore,(M.P.),India