标准摘要
[中文适用范围]： 本文件规定了 ISO 英制螺纹（UN 和 UNR）的基本轮廓和设计轮廓。UN 适用于内螺纹和外螺纹。UNR 仅适用于外螺纹。由于螺纹加工工艺，UN 螺纹的根部轮廓为平面或圆形，而 UNR 外螺纹的根部轮廓仅为定义的圆形。本文件适用于英制紧固螺纹。 [外文原描述]： This document specifies the basic and design profiles for ISO inch screw threads (UN and UNR). UN applies to both internal and external threads. UNR only applies to external threads. A flat or rounded root contour, due to the threading process, is specified for UN threads, while only a defined rounded root contour is specified for UNR external threads. This document is applicable to the inch fastening screw threads.
英文名称ISO general purpose screw threads — Basic and design profiles — Part 2: Inch screw threads