根据MA1370，本SAE航空航天标准（MA）提供了直“MJ”公制螺纹螺纹咬边的推荐尺寸数据。本文件中包含的螺纹咬边数据主要用于在螺纹处于盲孔或螺纹靠近相邻肩部的位置提供螺纹刀具跳动间隙。对于需要颈缩的螺栓、螺钉或螺柱，不建议使用这些螺纹咬边；e、 例如，减少与螺纹相邻的柄，以改善其拉伸、冲击和循环载荷性能。

This SAE Aerospace Standard (MA) provides recommended dimensional data for screw thread undercuts for straight "MJ" metric screw threads in accordance with MA1370.The thread undercut data included in this document are primarily designed to provide a clearance for threading tool runout either where the thread is in a blind hole or where the thread is close to an adjacent shoulder. These thread undercuts are not recommended for bolts, screws, or studs which are required to be necked; e.g., reduced shank contiguous to the thread, to improve their tensile, impact, and cyclic load performance.