A container assembly comprising: i) a container having a cavity for holding a fluid and including a bottom portion, wherein the bottom portion includes a laminate material including a first aluminum sheet having a surface facing the cavity of the container, a second aluminum sheet having a surface facing an outside of the container, and a polymeric layer interposed between the first and second metal sheets; ii) an opening in the bottom portion extending through the first and second aluminum sheets for draining the fluid from the container; iii) a clinch nut attached to at least one of the first and second aluminum sheets, extending only into the cavity, and being configured for receiving a drain plug that seals the opening and provides a primary seal to prevent flow of the fluid; iv) a drain plug having a threaded shaft for sealing the opening and a flange surface; and v) an elastomeric seal (45, 56) contacting the flange surface of the drain plug and the outside surface of the second aluminum sheet; wherein the container assembly is an oil pan assembly; preferably the fluid is a liquid; preferably the bottom portion is formed of the laminate material; preferably the first aluminium sheet is an interior aluminium sheet or/and the second aluminium sheet is an exterior aluminium sheet, preferably, the clinch nut is attached to at least the first aluminium sheet, and more preferably to both the first and second aluminium sheets, preferably the laminate has a stamped configuration. i) a container having a cavity for holding a fluid and including a bottom portion, wherein the bottom portion includes a laminate material including a first aluminum sheet having a surface facing the cavity of the container, a second aluminum sheet having a surface facing an outside of the container, and a polymeric layer interposed between the first and second metal sheets; ii) an opening in the bottom portion extending through the first and second aluminum sheets for draining the fluid from the container; iii) a clinch nut attached to at least one of the first and second aluminum sheets, extending only into the cavity, and being configured for receiving a drain plug that seals the opening and provides a primary seal to prevent flow of the fluid; iv) a drain plug having a threaded shaft for sealing the opening and a flange surface; and v) an elastomeric seal (45, 56) contacting the flange surface of the drain plug and the outside surface of the second aluminum sheet; wherein the container assembly is an oil pan assembly; preferably the fluid is a liquid; preferably the bottom portion is formed of the laminate material; preferably the first aluminium sheet is an interior aluminium sheet or/and the second aluminium sheet is an exterior aluminium sheet, preferably, the clinch nut is attached to at least the first aluminium sheet, and more preferably to both the first and second aluminium sheets, preferably the laminate has a stamped configuration. wherein the container assembly is an oil pan assembly; preferably the fluid is a liquid; preferably the bottom portion is formed of the laminate material; preferably the first aluminium sheet is an interior aluminium sheet or/and the second aluminium sheet is an exterior aluminium sheet, preferably, the clinch nut is attached to at least the first aluminium sheet, and more preferably to both the first and second aluminium sheets, preferably the laminate has a stamped configuration.