ISO 9974-4:2016规定了与ISO 9974一起使用的公制外六角和内六角端口插头的尺寸和性能要求1个端口。 根据本文件的端口塞可在63 MPa[630 bar[1]]的工作压力下使用。允许的工作压力取决于堵头端部尺寸、材料、设计、工作条件、应用等。 符合本文件中的尺寸信息并不保证额定性能。 注:本文件介绍了用于液压流体动力应用中新设计的端口和螺柱端的建议。 [1] 1巴=0.1 MPa=105 Pa；1 MPa=1 N/mm2。

ISO 9974-4:2016 specifies dimensions and performance requirements for metric external hex and internal hex port plugs for use with ISO 9974？1 ports. Port plugs in accordance with this document can be used at working pressures up to 63 MPa [630 bar[1]]. The permissible working pressure depends upon the plug end size, materials, design, working conditions, application, etc. Conformance to the dimensional information in this document does not guarantee rated performance. NOTE The Introduction of this document gives recommendations for ports and stud ends to be used for new designs in hydraulic fluid power applications. [1] 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.