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The objective of this research is to examine the mechanical properties and micro structure of body valve bolts of the alloy steel grade B7 material after being applied for more than 12 months by offshore location. The experimental steps conducted in the research were specimens check based on maker specification, preparation of specimens, tensile and hardness tests for mechanical properties and metallography for micro structure, analysis and conclusion. The total specimens used were 18 bolts. Based on the research, it was found that the tensile strength and hardness were 94.9 kgf/mm2 and 30.0 HRC respectively, the micro structure was consisting of ferit and pearlit. Comparing the result of testing of the used body valve bolts to the new ones and to the standard ones by ASTM A193, it can be concluded the used bolts remained re-useable on condition that there were no defect and corrosion existing.