This part of ISO 1179 specifies dimensions, performance requirements and test procedures for stud ends with ISO 228-1 threads and metal-to-metal sealing for general use only. These stud ends should not be used for leak-free hydraulic fluid power applications. Stud ends in accordance with this part of ISO 1179 may be used at working pressures up to 40 MPa (400 bar) for the S series, up to 25 MPa (250 bar) for the L series, and up to 10 MPa (100 bar) for the LL series. The permissible working pressure depends upon size, materials, design, working conditions, application, etc.