Head screw for fastening of cylinder-head cover of internal combustion engine, has nylon seal attached detachably at contact surface of head, and annular groove retaining nylon seal and arranged in surface

摘要

The screw has a shank, and a head with a contact surface, where a nylon seal (12) is attached detachably at the surface. An annular groove for retaining the seal is arranged in the surface. An inner edge (14) of the groove is radially approximated to the shank in such a manner that the seal lies at the shank. An outer edge (13) of the groove is spaced from an outer end of the surface in such a manner that a seal-free surface exists between the groove and the outer end in an installed condition.