自攻螺钉预孔的参考值

自攻螺钉预孔的参考值（参考件摘自SJ2495-84附录A）本文推荐了不同尾端形状自攻螺钉的用于不同材料的预孔参考值，以供选择。因材料与加工方法的不同，预孔值也必须相应改变。预孔直径小于或等于2倍金属板厚时，建议使用C型，F型螺钉，表中带括号的数字只适用于F型螺钉。注：自攻螺钉按头部形状，分为C型（尖头）、F型（平头）、FT型（带刃口）三种。预孔尺寸的偏差为H12。表A1对应于C型、F型螺钉的预孔值 mm螺纹规格料预 孑L 直 径钢不锈钢锰铁合金黄铜铝合金冲孔或模压孔径钻孔或光滑冲孔冲孔或模压孔径钻孔或光滑冲孔冲孔直径钻孔直径冲孔直径钻孔直径ST2.20.401.60.461.60.601.71.60.801.81.60.951.851.61.21.851.71.51.91.8ST2.90.42.22.2（0.46）2.22.20.6(2.5)2.30.8(2.5)2.42.20.95(2.5)2.42.21.22.52.21.52.62.31.92.652.3(2.7)(2.4)ST3.50.42.82.60.462.82.60.62.82.72.80.82.82.72.82.60.952.82.82.82.6(1.2)2.82.82.61.52.952.71.93.052.82.7(3.25)2.83.25-6.353.05螺纹规格料预 孑L 直 径钢不锈钢锰铁合金黄铜铝合金冲孔或模压孔径钻孔或光滑冲孔冲孔或模压孔径钻孔或光滑冲孔冲孔直径钻孔直径冲孔直径钻孔直径ST4.20.463.50.603.53.23.50.83.53.23.53.00.953.53.23.53.11.23.53.33.53.31.53.53.52.03.63.62.7(3.8)(3.76)3.2(3.8)(3.76)3.4(3.9)(3.8)4.1-9.5(3.9)ST4.80.53.960.63.963.63.960.83.963.63.960.93.963.73.963.61.23.963.83.963.61.53.83.62.03.963.72.7(4.06)(3.7)3.2(4.3)(3.9)3.4(4.3)(3.9)4.2(4.4)(4.0)5-9.5(4.2)ST5.50.64.20.84.74.20.94.74.21.24.74.34.11.54.74.54.22.04.64.42.74.74.63.2(5.0)4.63.4(5.0)4.64.2(5.1)4.85-9.55.0ST6.30.85.24.90.95.24.91.25.24.91.55.05.02.05.15.062.7(5.2)5.13.2(5.7)5.23.4（5.7）5.34.2（5.9）5.34.7（5.9）5.55-9.5（5.9）5.7浸渍树脂：胶合板层压布板螺纹规格孑L 径材料厚度盲孑L深度最 小最 小最 大ST2.21.93.24.813ST2.92.64.86.516ST3.53.14.86.516ST4.23.74.86.519ST4.84.26.4&025ST5.54.9&09.525ST6.35.7&09.525表A3对应于C型、F型螺钉石棉制品的预孔值 mm螺纹规格孑L 径材料厚度盲孑L深度最 小最 小最大ST2.21.93.24.813ST2.92.64.86.516ST3.53.14.86.516ST4.23.7&09.520ST4.84.2&09.520ST5.54.9&09.525ST6.35.7111325表A4对应于F型螺钉的预孔值 mm铸造材料：铝、镁、锌、黄铜、青铜螺纹规格孔径最小盲孔深度ST2.22.03.2ST2.92.64.8ST3.53.26.5ST4.23.96.5ST4.84.46.5ST5.55.07.0ST6.35.99.5螺纹规格酚醛树脂醋酸纤维、硝酸纤维、丙烯酸树脂孑L 径最小盲孔深度孑L 径最小盲孔深度ST2.22.04.82.04.8ST2.92.56.52.46.5ST3.53.26.53.06.5ST4.23.8&03.6&0ST4.84.4&03.8&0ST5.55.09.54.89.5ST6.35.99.55.69.5表A6对应于FT型螺钉的模铸锌和铝预孔值 mm螺纹规格材料厚度孑L 径螺纹规格材料厚度孑L 径ST2.91.51.9ST4.33.24.22.11.93.64.22.81.954.84.23.21.956.44.33.61.95&04.35ST2.92.82.59.54.353.22.6ST5.53.24.93.62.63.64.94.82.64.84.96.42.656.45.0ST3.53.23.0&05.03.63.09.55.04.83.0ST6.33.25.66.43.23.65.6&03.24.85.6ST4.23.23.86.45.73.63.8&05.74.83.89.55.76.43.9&03.9表A7对应于FT型螺钉的塑料制品预孔值 mm螺纹规格酚醛树脂醋酸纤维、硝酸纤维、丙烯树脂、苯已烯树脂孑L径盲孔深度孑L径盲孔深度最小最大最小最大ST2.22.02.46.41.92.46.4ST2.92.73.2&02.63.2&0ST3.53.24.89.53.04.89.5ST4.23.76