Tests of Shearing Mechanism of Safety Pins Used in Safety Couplings

Abstract The paper presents an analysis of issues related to improper shearing of safety pins used in overload couplings. Based on FEM computer simulations, it was established that the highest values of destructive stresses occur at the site of the structural narrowing. Experiments regarding the shearing of safety pins were carried out on a specialized test stand. 4 batches of pins of different hardness and 1 batch of reference pins were subjected to strength tests. Based on the conducted tests, it was established that the hardness of the pin material, which defines the form of the separating fracture, has a significant impact on the correct shear process of the pins. The paper also presents technological and design recommendations that should ensure an appropriate form of decohesion of the safety pin.