Abstract
Our previous reports clearly show that the loosening rotation can occur even if the magnitude of slip on bearing surfaces of bolt-nut joints would be very minute. From a series of studies on this theme basing on the experiments under transversely repeated quasi-static loading, this report deals with experimental considerations about difference of locking performance brought by different conditions of test samples. Noticeable points are difference in using coarse and fine threads, effect of using a plain washer, and effect of using a nut with flange. The results show that in locking performance in the case of minute slip of the bearing surface pretty large differences exist between the above test conditions.
