文档介绍：公称口径外径普通钢管加厚钢管mmin公称尺寸mm允许偏差壁厚理论重量kg/m壁厚理论重量kg/m公称尺寸mm允许偏差%公称尺寸mm允许偏差%6810**********/81/43/81/23/4111/411/±+12-+12-.±1% 每寸牙数   大径     中径     小径     建议底孔      基准距离      牙数1/8        27                                           18                                         18                                         14                                         14                                                                        -1/4                                    -1/2                                    (G)系列螺纹丝套规格、型式尺寸及安装参数表管螺纹规格公称直径螺距公称长度钻孔深度攻丝深度钻孔直径(mm)L1(mm)L2(mm)切削丝锥挤压丝锥尺寸牙数nd(mm)p(mm)xdL(mm)minminminmaxminmax1/...9