???????????????????????????????????????????????????????????????????
???????????12Tpi???????25.4mm??12?????????2.1mm ??????60????????????10???????????????14Tpi???????????60??????????15????????????????15??????????????????????????????1.8mm ?
????:
??????416mm ?????500??????????????279.4mm ???0.5mm ???????60.3mm?????????25.4mm??12?????????2.1mm ??????60????????????10?????????????????????????????????????????