1.1 本规范涵盖了最高质量的圆形和异形铬钒合金钢气门弹簧线，质量和回火均匀，用于制造气门弹簧和其他在适度高温下使用时需要高疲劳性能的弹簧。它类似于用于高疲劳水平的VD级（EN 10270-2中引用）。该钢丝应处于买方规定的退火和冷拔或淬火和回火状态。 1.2 以国际单位制或英寸-磅单位表示的值应单独视为标准值。 每个系统中所述的值可能不是完全等效的；因此，每个系统都应独立使用。将两个系统的值结合起来可能会导致不符合标准。 1.3 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。

1.1 This specification covers the highest quality of round and shaped chromium-vanadium alloy steel valve spring wire, uniform in quality and temper, intended for the manufacture of valve springs and other springs requiring high-fatigue properties when used at moderately elevated temperatures. It is similar to the grade VD (referenced in EN 10270-2) intended for high fatigue levels. This wire shall be either in the annealed and cold-drawn or quenched and tempered condition as specified by the purchaser. 1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.3 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.