統(tǒng)一國家標(biāo)準(zhǔn)粗牙螺紋 unc unified national coarse thread: 統(tǒng)一標(biāo)準(zhǔn)粗牙螺紋unified coarse thread: 統(tǒng)一標(biāo)準(zhǔn)粗牙螺紋national coarse thread: 國家標(biāo)準(zhǔn)粗牙螺紋; 美制粗牙螺紋unf unified national fine thread: 統(tǒng)一標(biāo)準(zhǔn)細(xì)牙螺紋nc america national coarse thread: 美制粗牙螺紋下載手機(jī)詞典可隨時隨地查詞查翻譯