ASTM A671 Standard Specification for Electric-Fusion-Welded Steel Pipe for Atmospheric and Lower Temperatures.ASTM A671 specification covers standard requirements for electric-fusion-welded steel pipe with filler metal added, for atmospheric and lower temperatures. The steel pipe shall be fabricated from a pressure vessel quality plate of several analysis and strength levels. Several grades and classes of pipe shall be provided.ASTM A671 Standard main steel grade:CC70,CC60,CB70,CB65,CB60 and so on.