Aircraft components have different functions and characteristics, for example, the bolt and nut pressure switch of Cessna Grand Caravan 208B, which functions to determine the pressure of oil and fuel flowing. At the end of the bolt and nut, there is a small hole to press the sensor in the component, then the result of the pressure will be converted to the system and sent to the indicator located in the cockpit, so the pilot sees the actual in the cockpit. The purpose in this research was to determine the characteristics of the bolt and nut pressure switch. This study used chemical composition, Vickers hardness, and metallographic testing methods. The test results of the chemical composition of bolt and nut on the pressure switch of Cessna Grand Caravan 208B, show that the elements, iron (Fe) = 67.58% and chromium (Cr) = 17.04%, are the dominant elements, therefore it is included as an alloying element of Fe-Cr. The test an average hardness value of 254.64 VHN. These values were obtained from the total percentage of iron 67.58% and chromium 17.04%. Chromium (Cr) is an element that can increase the hardness of carbon steel and increase corrosion resistance. Therefore, the hardness of the bolt and nut pressure switch of Cessna Grand Caravan 208B is high due to the addition of Cr which help the main element, Fe, properties. The novelty of this study is the dominant presence of chromium, so the properties of this material are hard, heat resistant, and corrosion resistant