Generally, rivets are subjected to shear only, but bolts may be stressed by shear and tension. There is internal shear in all parts being bent such as the skin of sheet metal structures. In Type 1 the fulcrum is located between the applied effort and the resistance. In Type 2 the resistance is located between the fulcrum and the applied effort. In Type 3 the applied effort is located between the resistance and the fulcrum.
Mechanical advantage is the ratio between the resistance and the effort applied to a lever.
Proper use of mechanical advantage enables a relatively small force to overcome a larger resisting force by applying the effort through a longer distance than the resistance is moved. Thus, the applied effort in the example would move through a distance that is four times greater than the distance the resistance would move. Moment of Force A moment of force is the product of a force or weight and a distance. If the moment of force of the applied effort equals the moment of force of the resistance, the lever will balance. Any type of machine vibrates.