scope:

This part of IS0 9974 specifies dimensions, performance requirements and test procedures for heavy-duty (S series), light-duty (L series) and extra-lightduty (LL series) stud ends with IS0 261 threads and metalto- metal sealing. It also specifies the designation of these stud ends. These stud ends should not be used for leak-free hydraulic fluid power applications because they may leak if re-used.

Stud ends in accordance with this part of IS09974 may be used at working pressures up to 10 MPa (100 bar ¹⁾) for the LL series, 25 MPa (250 bar) for the L series and 40 MPa (400 bar) for the S series. The permissible working pressure depends upon the stud end size, materials, design, working conditions, application, etc.

For threaded ports and stud ends specified in new designs in hydraulic fluid power applications, only IS06149 is to be used. Threaded ports and stud ends in accordance with IS0 1179, IS0 9974 and IS0 11926 are not to be used for new designs in hydraulic fluid power applications.

Conformance to the dimensional information in this part of IS0 9974 does not guarantee rated performance. Each manufacturer should perform testing according to the specification contained in this part of IS0 9974 to assure that components comply with the performance ratings.

1) 1 bar = 0.1 MPa = 10⁵ Pa; 1 MPa = 1 N/mm²