Protective plastic pipe end fitting system adapted to be mounted at an end portion of a protective plastic pipe into which at least one elongated object passes, the fitting system being adapted to provide a seal that prevents transfer of fluid into and/or out of the protective plastic pipe, wherein the fitting system comprises: - a housing composed of one or more rigid plastic housing parts, - a compressible sealing member, wherein the housing delimits a pipe bore that is adapted to receive therein an end portion of a protective plastic pipe, the pipe bore having an insertion end for axial insertion of the end portion of the protective pipe, wherein the housing delimits a sealing member receiving chamber that is adapted to receive therein the sealing member in a non-compressed condition, said chamber being arranged in line with the pipe bore and opposite the insertion end of the pipe bore, wherein the compressible sealing member has an annular sealing member body, said body having a pipe contacting end face and a counter end face opposite said pipe contacting end face, said sealing member body having at least one axial passage therein, said at least one axial passage being configured to receive an elongated object passing there through, wherein the annular sealing member body is split and the pipe bore is laterally open allowing to mount the sealing member and the housing about an elongated object that extends from the end portion of the protective pipe into which the elongated object has already been inserted and to then slide the fitting system towards the protective pipe so that the protective pipe enters the pipe bore via the insertion end thereof, wherein the housing has a least one first engaged helical thread creating portion that is arranged in the pipe bore, which first engaged helical thread creating portion is first into engagement with the end portion of the protective plastic pipe upon said entry of the protective plastic pipe into the pipe bore via the insertion end thereof and which first engaged helical thread creating portion is adapted to create a helical thread having a lead into the exterior of the protective plastic pipe upon screwing the fitting system onto the end portion of the protective plastic pipe, so that the end face of the protective plastic pipe comes into contact with the pipe contacting end face of the sealing member, wherein upon continuing said screwing the compressible sealing member becomes compressed and seals onto the end of the protective plastic pipe, characterized in that the first engaged helical thread creating portion has an asymmetric cross-section defined by a low inclination stab flank, a crest ridge, and a steep load flank. wherein the fitting system comprises: - a housing composed of one or more rigid plastic housing parts, - a compressible sealing member, - a housing composed of one or more rigid plastic housing parts, - a compressible sealing member, wherein the housing delimits a pipe bore that is adapted to receive therein an end portion of a protective plastic pipe, the pipe bore having an insertion end for axial insertion of the end portion of the protective pipe, wherein the housing delimits a sealing member receiving chamber that is adapted to receive therein the sealing member in a non-compressed condition, said chamber being arranged in line with the pipe bore and opposite the insertion end of the pipe bore, wherein the compressible sealing member has an annular sealing member body, said body having a pipe contacting end face and a counter end face opposite said pipe contacting end face, said sealing member body having at least one axial passage therein, said at least one axial passage being configured to receive an elongated object passing there through, wherein the annular sealing member body is split and the pipe bore is laterally open allowing to mount the sealing member and the housing about an elongated object that extends from the end portion of the protective pipe into which the elongated object has already been inserted and to then slide the fitting system towards the protective pipe so that the protective pipe enters the pipe bore via the insertion end thereof, wherein the housing has a least one first engaged helical thread creating portion that is arranged in the pipe bore, which first engaged helical thread creating portion is first into engagement with the end portion of the protective plastic pipe upon said entry of the protective plastic pipe into the pipe bore via the insertion end thereof and which first engaged helical thread creating portion is adapted to create a helical thread having a lead into the exterior of the protective plastic pipe upon screwing the fitting system onto the end portion of the protective plastic pipe, so that the end face of the protective plastic pipe comes into contact with the pipe contacting end face of the sealing member, wherein upon continuing said screwing the compressible sealing member becomes compressed and seals onto the end of the protective plastic pipe, characterized in that the first engaged helical thread creating portion has an asymmetric cross-section defined by a low inclination stab flank, a crest ridge, and a steep load flank.