dia 1/2 inch sch 40s的管子是什么规格,dia是内径还是外径还是公称直径?

dia 1/2 inch sch 40s的管子是什么规格,dia是内径还是外径还是公称直径? 英语翻译1 Pipe sch 40,20 dia ASTM 106 GR-B OR API 5L GR-B,Seamless Beveled End.20ft Long 8 lg 2 Pipe sch 40,12 dia ASTM 106 GR-B OR API 5L GR-B,Seamless Beveled End.20ft Long 2 lg 3 Pipe sch 40,10 dia ASTM 106 GR-B OR API 5L GR-B,Seamless Beve PIPE 100 DIA SCH 40*75 LG什麽意思 2 sch.40镀锌钢管,2 sch. DIA.S.S.ROUND 1/2N.B.SCH. 8 1/2-inch-by-11-inch buy 8 1/2-inch-by-11-inch spiral notebook) inch/s是什么单位 PIPE 1.25X 24 C.S.SCH.40 dia . DIA 1feet inch ,1inch cm 1/4 inch inch color SHARP CCD 英语翻译The steel is not a critical spec' it's merely ERW re-drawn tube 4inch Dia x 16g wall or alternatively 100mm Dia x 1.5 wall以上是原文,我大致翻译了钢铁并不是一个关键的规格'这只不过是电阻焊重新割制的钢管 8” SCH 40钢管, DIA.S.S.ROUND BAR是什么 1inch 多少厘米 1inch是多少厘米?