Abstract: A rim structure for a metal container wherein the rim is an integral part of the container cylindrical sidewall. The rim has an outwardly projecting wall which is radially inwardly folded by a top fold over onto itself and is then vertically folded upwardly and thereafter radially outwardly folded to define a generally triangle-shaped cross section. The top of the triangle is extended above the top fold. This configuration defines an internal step at the mouth of the container, its top portion is flexible due to the free outwardly deflection of the vertically internal length determining the step. This resiliency allows an annular projection on the container lid to be snap-fitted through the step.