1.1 本规范涵盖用于中速柴油和天然气发动机的连续晶粒流锻造碳钢和合金钢曲轴。 1.2 用于制造锻件的钢材需要进行真空脱气。 1.3 除非买方另有规定，否则给定强度等级的钢成分等级通常由锻件供应商选择。 1.4 规定对曲轴的指定表面进行处理，以提高疲劳强度或耐磨性，或两者兼而有之。 1.5 除本规范特别要求外，规范的所有规定 A788/A788M 申请 1.6 除非订单规定了适用的“M”规格名称，否则材料应以英寸-磅为单位提供。 1.7 以英寸-磅单位或国际单位制（公制）表示的数值应单独视为标准值。在文本和表格中，国际单位制显示在括号中。每个系统中规定的值不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。

1.1 This specification covers continuous grain flow forged carbon and alloy steel crankshafts for medium speed diesel and natural gas engines. 1.2 The steel used in the manufacture of the forgings is required to be vacuum degassed. 1.3 The choice of steel composition grade for a given strength class is normally made by the forging supplier, unless otherwise specified by the purchaser. 1.4 Provision is made for treatment of designated surfaces of the crankshaft to provide enhanced fatigue strength, or wear resistance, or both. 1.5 Except as specifically required in this specification, all provisions of Specification A788/A788M apply. 1.6 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound units. 1.7 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as standard. Within the text and tables the SI units are shown in brackets. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.