How can we find a relation between welding bead and outer diameter of a pipe? Welding bead is inside of the pipe and I am using M.S. pipe.

Dimensions are listed below:

Pipe OD=25.4mm


Bead Length=1.5mm

Bead Height= 1.5mm

Mandrel OD=19mm

enter image description here

I need to bend pipe but welding bead is not allowing mandrel to bend and all I need is to find a relation between welding bead and outside diameter of pipe. Do we have standard for that?

  • $\begingroup$ Use a pipe without a bead. $\endgroup$
    – Solar Mike
    Commented Jun 26, 2022 at 19:01
  • $\begingroup$ This is constraint. $\endgroup$ Commented Jun 26, 2022 at 19:03
  • $\begingroup$ @SolarMike i need to find a relation between these. $\endgroup$ Commented Jun 26, 2022 at 19:03
  • $\begingroup$ Do you mean how far the bead protrudes into the ID of the pipe? Welded pipe normally has no bead, it's resistance welded. The normal spec would be you can't even see the seam. You shoud talk to the manufacturer. $\endgroup$
    – Tiger Guy
    Commented Jun 26, 2022 at 19:20
  • $\begingroup$ @TigerGuy you can see bead in the picture. Do we have any standard for that? I have to bend pipe and this bead in not allowing mandrel to bend. $\endgroup$ Commented Jun 26, 2022 at 20:39

3 Answers 3


Looks like ERW pipe with the ID trim die not working. The diameter is very small for DSAW ( double submerged arc welded) pipe and the ID weld bead looks too high. Or, I am wrong and it was welded from the outside only. DSAW ; D means double, welded from outside and inside. I have seen a brazillion lengths of pipe and never saw one with a weld profile like that ( outside weld only). What does M.S. mean ? The pipe standard is whatever standard to which it was ordered. I promise you it does not meet API 5 CT or 5 L. I would be amazed if it conforms to any ASTM specifications.

  • $\begingroup$ M.S. is Mild Steel. Just want to know do we have a relation between welding bead and OD of pipe? $\endgroup$ Commented Jun 27, 2022 at 3:35

There is no relation between welding bead and OD of pipe

There is no relation because pipe is not supposed to have a bead inside it. Either you bought defective pipe, or you're in a locale where pipes are made however people want to. Purchase your next pipe to just about any standard and it won't look like that.


A Weld Bead is not a defect, and in fact is necessary to expel all of the Oxide impurities formed during the Resistance Welding Process. The issue is with the Purchase Order and/or Drawing. ID and/or OD Scarfing must be ordered. If you do not order the Tubes that way, then the manufacturer will not add that to the process. It is cheaper and easier for them to run the Tubes with the Weld Beads and no Scarfing.


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