Abstract: Provided is a rear guard structure system including: a chassis frame attached to the bottom of a vehicle; a plurality of guard stays having one ends hinge-coupled to chassis-frame hinges at both sides of the chassis frame through first hinges; and a rear guard attached to the other ends of the guard stays. A first stopper is mounted around the first hinge so as to restrict rotation of the guard stay, and includes a first buffer member to reduce shock or vibration when the rear guard is vertically vibrated.

Abstract: Provided is an apparatus for measuring axial force and frictional torque of a threaded part, including: a fastening member having a threaded hole through which an external threaded part passes, and coming into contact with a head of the external threaded part fitted into the threaded hole; a support body supporting the fastening member; an internal threaded part engaging with an external threaded part fitted into the fastening member and spaced apart from the fastening member; a load cell fixedly supporting the internal threaded part and measuring axial load and frictional torque that are transmitted from the external threaded part to the internal threaded part; and a torque application unit applying torque to the external threaded part.