An American National Standard. The American Society of Mechanical Engineers (ASME). Revision. redesignation, and consolidation of ASME B18.2.3.7M-1979 (R2006) and ASME B18.2.4.6M-2010. Date of Issuance: March 23, 2012. 20 p. This Standard covers the complete general and dimensional data for products in the metric series recognized as American National Standard for sizes M12 through M36.