Abstract: In many assemblies it is desirable to provide a strain relief device to grip an electric cord to prevent longitudinal motion of the cord, with respect to the strain relief device. The disclosed strain relief member surrounds the electric cord and is enclosed within a body member which, when assembled, applies longitudinal compressive forces on said strain relief member to cause a central portion thereof to collapse axially inward and grippingly engage the electric cord. The central portion may include serrations for improved restraining of the cord. The strain relief member may be made of plastic or metal and may include central perforations and/or portions of different thicknesses to facilitate and control the collapse. A metallic strain relief member may serve ground metal sheathed cable. A resilient membrane in a plane normal to the longitudinal axis of the cord and the strain relief member may be used between the strain relief member and the body member to provide a liquid tight seal.