Some of the types of first-class levers include crowbars, scissors, seesaws, fishing rods, pliers, balance scales, trebuchets and hammers when removing nails. All of these levers have a fulcrum positioned between load and effort. First-class levers are the most common type of levers.
A force must be applied over a long distance in order to make the load move. The mechanical advantage of first-class levers is controlled by adjustment of the distance between the load and the fulcrum. The closer the fulcrum is to the load, the more force is required to cause an impact on the load.