inner outer thickness density weight
washer1025.437.8510.07824
across flat hole diameter thickness flange dia flange thickdensity weight hex nut22.29117.8531.36357 AF hole dia thickness density weight
square nut8437.851.211412
head AF head height washer dia washer thick body dia body length thread dia screw60.324.60038.1203.2
形状差不多都可以.只要不是奇型怪异的都可以用
铜的密度：8.5
不锈钢的最好用7.95
一般的钢铁制品，用7.85g/cm3
thread length density
7.852425.737