"This SAE Standard provides basic information on the International System of Units@ abbreviated SI in all languages@ and its application in engineering practice and measurement unit usage. The purpose is to provide within the body of SAE's authoritative resource material@ information on SI and guidance on SI's correct@ uniform usage in its application to land@ sea@ and air design@ engineering@ and manufacturing practices. This document establishes the rules for the use of SI units in SAE technical reports@ including standards@ recommended practices@ information reports@ as well as technical papers@ publications@ etc. SAE J916 also is designated as applicable to all SAE operations@ internal and external communications@ products@ and services for governance of SI metric practice. By direction of the SAE Board of Directors (Metric Policy approved in June@ 1990) ""... metric (SI) units will be the only system used for expressing weights an measures... all boars and committees will fully convert to this system by December 31@ 1992 ... certain exceptions to this policy will necessarily occur when conversion to SI metric is not practical..."" Throughout this document@ SI is intended to include recognized SI units@ as established by the international General Conference on Weights and Meausres2 (CGPM)@ and a limit number of other units that@ formally@ are not SI units. SI forms the foundation of international metric standardization@ but it is recognized worldwide that certain exceptions are required. For example@ the degree (of plane angle)@ the minute@ and the hour are non-SI units. It is the purpose of this standard to set forth proper SI metric practice for SAE use@ purpose of this standard to set forth proper SI metric practice for SAE use@ and to give specific guidance concerning the acceptable use of non-SI units in SAE. 2 CGPM Resolutions and Recommendations are published in NBS Special Publication 330@ ""The International System of Units. (SI)."