The function of the indicator Stud bolt is to evidence at all times the dynamic stresses that it undergoes and if these stresses are within the limits of the design of the system. The values that are verified are the length variations of the torque element; this variation is a direct relation of the following two parameters:

Indicator studbolts can be made in low-alloy,austentic,ferritic steels,duplex and superduplex grades, in relation to the ambient conditions.

For alloy steel studbolts it is best to use for the indicator rods materials such as Alloy C-276 whose K coefficient is similar if not the same to that of the material used for the studbolt.