A barrel washer comprising a convex portion, a concave portion, the concave portion configured to mate with the convex portion, such that the convex portion is only capable of rocking along a single axis within the concave portion. The barrel washer may be configured to prevent a bolt from rotating within the barrel washer. The barrel washer may be configured to relieve bending stress on the bolt as well as extraction of the bolt from the barrel washer. A surface of the concave portion may be coated with a lubricant. A surface of the convex portion may be coated in a lubricant. The barrel washer may be configured to couple a bolt to a flange that is couple to another flange. The convex portion may comprise a rocker. The barrel washer may be configured relieve bending stress on the bolt as a first flange moves relative to a second flange.