History, Uses, and Physical Characteristics of Steel Pipe
of Steel Pipe HISTORY _____ ... Lock-Bar pipe had notable advantages over riveted pipe: it had only one or two straight seams and no round seams. The straight seams were con-sidered 100-percent efficient as compared to the 45-percent to 70-percent efficiency for riveted seams. Manufactured in sizes from 20 in. (500 mm) through 74 in. (1,850 mm),