Structural irregularities is also a big factor which would decide the magnitude of the stress. Hence ignoring this can be a big factor towards causing fatigue failure of the equipment. For example, if there is a shape which ends in a square will surely have more stress acting on it and will act as an initiator for fatigue failure.
Overall dimensions or the size of the equipment is also a key factor in this regard. The dimension plays a key role here. If the size is big then it naturally results in lower fatigue limits. Hence bigger the dimensions of the equipment more precautions have to be taken to prevent fatigue failure.
Carburizing and Nitriding Process: These are the process of surface hardening. In this process, the core material is exposed to carbon and nitrogen-rich atmosphere at high temperatures. Hence creating a layer of hard material over the surface. This protects the underlying surface to a greater degree.
The extent of stress: The frequency at which the material is exposed to stress is also a key point to be noted. Please note that fatigue fracture does not occur with little exposure to stress. It requires lots of exposure for the material to break. Hence it is important to note the amount and frequency of stress also.
Tensile strength is also an important factor to be noted in order to prevent fatigue failure. If the tensile strength is of intermediate nature then the material will be more prone to failure.however having a proper compressive strength, on the other hand, protects the material.
Residual compression stress has to be taken care off. It will help in the location of weak points considerably.
Take care of fretting: Fretting happens when the overall surface is uneven. Due to this, the chances of fatigue failure are enhanced by many folds.