本SAE标准涵盖了汽车及相关行业中使用的灰铸铁砂型铸件的硬度、抗拉强度、微观结构和特殊要求。对铸件的硬度提出了具体要求。提供试棒抗拉强度/布氏硬度（t/h）比要求，以建立每个等级的一致抗拉强度-硬度关系，以便于预测和控制铸件的抗拉强度。规定了特殊应用和使用条件所需的灰铸铁汽车铸件的特殊附加要求规范。注:本文件于1993年修订，以提供特定等级的t/h控制。1999年，该文件进行了修订，使国际单位制成为主要的公制单位。 为了更好地将分级系统与长期采用的生产方法和生产的等级保持一致，1999年将以前的拉伸强度和硬度固定组合分级系统改为试验棒t/h比和铸件硬度等级可变组合分级系统。硬度等级的数量相对于先前可用范围的数量有所增加，以促进铸件平均硬度在规范范围内的居中，从而将成本优化对规范范围低侧或高侧附近控制的依赖性降至最低。

This SAE Standard covers the hardness, tensile strength, and microstructure and special requirements of gray iron sand molded castings used in the automotive and allied industries. Specific requirements are provided for hardness of castings. Test bar tensile strength/Brinell hardness (t/h) ratio requirements are provided to establish a consistent tensile strength-hardness relationship for each grade to facilitate prediction and control of tensile strength in castings. Provision is made for specification of special additional requirements of gray iron automotive castings where needed for particular applications and service conditions.NOTE - This document was revised in 1993 to provide grade specific t/h control. In 1999 the document was revised to make SI metric units primary. To better align the grading system with long established production methods and grades produced, the previous system of grading by fixed combinations of tensile strength and hardness was changed in 1999 to a system of grading by variable combinations of test bar t/h ratio and casting hardness grades. The number of hardness grades was increased relative to the number of previously available ranges to facilitate centering of casting mean hardness in the specification range so that dependence of cost optimization on controlling near the low or high sides of specification ranges is minimized.