The reamed bolt with code number K 32390 is a precision-engineered fastener used in the pinion shaft assembly of the Adriadiesel/Jugoturbina/Zgoda/Sulzer ZV40/48 diesel engine. Unlike standard bolts, reamed bolts are manufactured with exact diameter tolerances to fit tightly into mating holes, eliminating play and ensuring perfect alignment under dynamic load conditions. This bolt plays a critical role in maintaining the integrity of the gear system, preventing shifting or loosening of components during prolonged engine operation. Its strength and precision are vital to the reliability and performance of the power transmission mechanism.