The mechanical indicators consist of some basic types that belong to the most widely used tools of dimensional measurements in metalworking production . Although there are various other systems of displacement amplification, mechanical amplification provides many advantages in indicator applications. A few of these advantages aim at pointing out certain aspects that deserve consideration when selecting the best-suited type of instrument for a particular set of measuring conditions. It must be realized , however, that not all the advantages necessarily refer to all models of indicators. Nor are these advantages the exclusive properties of mechanical indicators , although the mechanical system of amplification lends itself best in utilizing the potentials of the described beneficial characteristics.