This SAE Information Report is an introduction to lubricant classifications, specifications, and types in common use today. It emphasizes the desirability of using a minimum number of lubricants. Pertinent SAE reports are called out for easy reference. Lubricant abbreviations have been included that will assist in preparation of lubrication charts (described in SAE J753). Table 1 lists the components of construction and industrial equipment and the various lubricants which may be used. Table 2 lists lubricant types and identifying abbreviations. Lubricants that had common usage in the past are retained in Table 2 to show where the new specifications originated.