实用文档之塑胶件自攻螺钉底孔标准实用文档之"自攻螺钉用注塑预制孔尺寸系列"注塑预制孔直径螺钉底径序号螺纹规格a类b类最小最大1ST1.50.90.80.840.912ST1.91.31.21.171.243ST2.21.61.51.521.634ST2.621.91.81.95ST2.92.32.22.082.186ST3.32.72.52.292.397ST3.52.82.62.512.648ST3.93.232.772.929ST4.23.63.22.953.110ST4.84.23.93.433.5811ST5.54.84.63.994.1...