This International Standard specifies the requirements of mineral oil hydraulic fluids and is intended for hydraulic systems, particularly for hydrostatic hydraulic fluid power application. The purpose of this International Standard is for the guidance of suppliers and end users of mineral oil hydraulic fluids and for the direction of equipment manufacturers of hydraulic systems. This International Standard is written in a general form so that its application can accommodate various climatic conditions throughout the world. This International Standard also stipulates the requirements of mineral oil hydraulic fluids at the time of delivery. Classification of fluids used in hydraulic applications is defined in ISO 6743-4. Of the categories covered by ISO 6743-4, six types only of mineral oil based fluids are embraced in this specification. These categories are: HH, HL, HM, HR, HV and HG. NOTE — Although specifications given in this International Standard refer only to mineral oil based hydraulic fluids, this specification can be applicable to certain types of hydrocarbon synthetic fluids e.g. polyalphaolefin (type HS).