M10x80. Mount bolt. PartQualifier: M10x80. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Engine Mount Crossmember to it's Mounting point. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Seat Belt Reinforcement to it's Mounting point. Attaches the Roll Bar to the floor, chassis or body structure. Engine Crossmember. FastENING Screw. Roll Bar. Seat Belt Reinforcement. Support.