In transmitting kinetic energy from the turbine to the generator, the coupling will experience stress and deformation, especially on the bolts that support the coupling. Therefore, it is important to analyze how the operational load of the turbine affects the strength of its bolt structure. The author has conducted a literature study and numerical simulation to analyze the problem. In the simulation that has been done, it was found that the maximum von misses stress and strain values received by the bolt were 196.34 MPa and 0.0009687 mm/mm at maximum loading. The relationship between operational load and von misses stress value is that if the operational load is higher, the von misses stress received by the bolt will also be higher. Furthermore, there is also a relationship between operational load and von misses strain value, namely that if the operational load is higher, the von misses strain received by the bolt will also be higher. DBy using AISI Type S5 Tool Steel – Oil Quenched to 55 HRC, a relationship was obtained between operational load and safety factor value. The relationship between operational load and safety factor value is that if the operational load is higher, the safety factor value will be lower. From the simulation that the author has done, it is found that there is a difference in safety factor if the material used in the bolt is changed. It was found that AISI Type S5 Tool steel - Oil Quenched to 55 HRC has a higher safety factor value of 8.8111.Meanwhile, the AISI Type S5 Tool Steel material, Austenitized 855 – 870°C (1575 – 1600°F), Oil Quenched to 45 HRC has a lower safety factor value, namely 5.7552.