This part of ISO 6743 establishes a detailed classification of family X (Greases) which belongs to class L (Lubricants, industrial oils and related products). It should be read in conjunction with ISO 6743-99[1]. This classification applies to categories of greases used for lubrication of equipment, components of machines, vehicles, etc. The greases have been classified according to the operating conditions under which they are used, because the versatile nature of grease makes it impractical to classify them according to the end use. It will therefore be necessary to consult the supplier to be certain that the grease can be used in, for example, rolling bearings or pumped supply systems, and also concerning the compatibility of products. In this classification, a grease cannot have more than one symbol. This symbol should correspond to the most severe conditions of temperature, water contamination and load in which the grease can be used. NOTE This part of ISO 6743 does not pretend to cover the classification of greases intended for very special applications. It is up to the end-user and the supplier to negotiate the applicability of such greases, on the basis of relevant laboratory and/or field testing.