Abstract: A snap-lid container, particularly in plastics material, of the pail type for fluid materials. A fluid-tight seal between the container and lid is effected by peripheral contact under pressure between a convex inner edge of the container lip and a splayed surface within a peripheral, inverted U-groove in the lid. Sealing pressure is provided by coaction between complementary sloping surfaces on the container lip and within the lid peripheral groove respectively which tends to draw the lid in a closing direction.