Abstract: Torque limiting clamping and sealing means comprise a cylindrical unthreaded screw-thread engaging clamping member of elastomeric material screwed on a rigid screw threaded member at an interference fit. An annular abutment around the clamping member engages a stop fixed with respect to the rigid member at a predetermined limit of screw induced axial travel to effect said limit of travel. A thin, flexible annular sealing lip around the clamping member and spaced radially from the abutment sealingly engages a surface fixed with respect to the rigid member prior to said limit of axial travel.