Seamless pipe as the name suggests is a pipe without a seam or a weld-joint in contrast to Seam or Welded pipe. In a Seam or Welded pipe, the seam or the weld-joint is the weaker part of the pipe limiting the strength of the pipe to the strength of the weld-joint. Whereas the seamless pipe does not have any such joint and thus has uniform structure & strength all over the pipe body.