本文件规定了六角凹头沉头螺钉的特性，该螺钉由钢和不锈钢制成，具有公制粗牙螺纹M2至M20，产品等级为A级，由于头部设计，其承载能力降低。 注1:ISO 888、ISO 965-1和ISO 4753中给出了其他尺寸选项。 注2:降低的承载能力（与沉头尺寸以及本文件中规定的六角套筒贯穿件相关）意味着极限拉伸载荷的限制；见表5。 注3:需要特别注意确保沉头与组件中沉孔的支承面对齐。

This document specifies the characteristics of hexagon socket countersunk head screws with reduced loadability due to head design, in steel and stainless steel, with metric coarse pitch threads M2 to M20, and with product grade A. NOTE 1 Other dimensional options are given in ISO 888, ISO 965-1 and ISO 4753. NOTE 2 The reduced loadability (related to the countersunk head dimensions in combination with penetration of the hexagon socket specified in this document) implies a limitation of ultimate tensile load; see Table 5. NOTE 3 Particular attention is needed to ensure alignment of the countersunk head with the bearing surface of the countersink in the assembly.