本文件规定了六角内六角带凸缘圆头螺钉的特点，由于头部设计，其承载能力降低，钢制，公制粗牙螺纹M3至M16，产品等级为A级。 如果在某些情况下需要其他规格，可从ISO 888或ISO 4753中选择尺寸选项。 注:降低的承载能力（与本文件中规定的头部尺寸和六角套筒贯穿件相关）意味着特定标记（性能等级前加零）显示的极限拉伸载荷限制。对于所有尺寸和所有属性类别，假设头部的可加载性为螺纹的80%，见表4。

This document specifies the characteristics of hexagon socket button head screws with collar, with reduced loadability due to head design, in steel, with metric coarse pitch threads M3 to M16, and with product grade A. If in certain cases other specifications are requested, dimensional options can be selected from ISO 888 or ISO 4753. NOTE      The reduced loadability (related to the head dimensions in combination with penetration of the hexagon socket specified in this document) implies a limitation of ultimate tensile load shown by a specific marking (property class preceded by a zero). The loadability in the head is assumed to be 80 % of that in the thread for all sizes and all property classes, see Table 4.