本SAE推荐实施规程旨在为挂车（尤其是全挂车和/或牵引车）的制造商和用户提供指南。不鼓励将其纳入州、联邦或任何缺乏修订灵活性的法律或法规。应急安全是本建议的基础。本SAE推荐规程涵盖了全挂车和/或牵引车安全链的数量、位置和连接方法。

This SAE Recommended Practice is intended as a guide for manufacturers and users of trailers, specifically full trailer(s) and/or converter dollies. Its inclusion in state, federal, or any laws or regulations where flexibility of revision is lacking is discouraged. Emergency safety is the basis of this recommendation. This SAE Recommended Practice covers the number, location, and method of attachment of safety chains for full trailers and/or converter dollies.