ISO 11158:2023

This document specifies the minimum requirements for new mineral oil hydraulic fluids and is intended for hydraulic systems, particularly for hydrostatic hydraulic fluid power application. The purpose of this document is to guide suppliers and end users of mineral oil hydraulic fluids and to direct equipment manufacturers of hydraulic systems. This document is written in a general form so that its application can accommodate various climatic conditions. This document also stipulates the requirements for mineral-oil hydraulic fluids at the time of delivery. This document is intended to be used in conjunction with ISO 6743-4, which classifies fluids used in hydraulic applications. Among the categories covered by ISO 6743-4, only five types of mineral oil-based fluids are covered in this document. These categories are HH, HL, HM, HV and HG. This document does not cover the extreme cases of use in terms of hydraulic circuits design, temperature and extreme conditions. NOTE          For use in exceptional conditions, suppliers and purchasers of lubricants can mutually agree upon additional testing methods and acceptability criteria of the products. .