The invention relates to a spring seat for a mechanical spring axle/suspension system that includes continuous window welds and facilitates the use of a thin-wall axle, thereby saving weight and cost. The seat secures at least one mechanical spring of the axle/suspension system to an axle of the axle/suspension system. The spring seat comprises at least one body configured to seat on the axle, and the body forms at least one window when disposed on the axle. The body is rigidly attached to the axle by a continuous weld formed in the window. The spring seat is free of a line weld between the body and the axle.