The investigation of a crack in a cantilever beam is very imperative in various mechanical applications such as turbo machinery impeller blades, propeller shafts and airplane wings. As a result, a full study is performed in this paper to investigate the crack consequences on a cantilever beam; this is carried out by monitoring the natural frequency of the beam, taking into consideration the probe mass used in data collection. The investigation is divided into two phases; the first phase is experimentally performed by measuring the natural frequency of a specimen with different thicknesses and widths while changing specimen material to illustrate the specimen dimensional and material effect on natural frequency reduction. This is carried out...