An energy absorber device including a plastic cylinder having a smaller and larger diameter portion with a shoulder at the junction therebetween, a screw-in plastic seal at one end of the casing surrounding a piston member, a metal housing having smaller and larger diameter portions for sliding engagement with the smaller and larger diameter portions of the casing and having a shoulder for abutting engagement with the shoulder on the casing, and an abutment member carried by the housing for engaging the outer end of the piston member.