My translation of a document published by the Pervouralsk New Pipe Plant:

Inspection of pipe-end root face (“face ring”)

Inspection of this type is carried out as required by the regulatory documentation using a ruler or a gauge.

Bevel angle inspection

Inspection of this type is carried out as required by the regulatory documentation using a [protractor? goniometer?] or a gauge.

What tool do we usually use to inspect bevel angles at the end of a pipe?

The Russian word used is "угломер", literally "angle-measurer". According to Multitran, it could be translated in dozens of ways.

(I'm translating the word "truba" as pipe despite some saying that "tube/tubing" is a more proper word: the reason is, the plant uses "pipe" throughout its English-language website)

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    $\begingroup$ What is the word you've translated as "gauge" and does it have any alternate translations? $\endgroup$
    – Air
    Jun 17, 2016 at 21:34
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    $\begingroup$ The term "ruler" sounds a bit odd. It tends to imply low-precision measurement, and it's not clear to me whether you meant a measuring device, or merely a "straight edge" to visually check that something is flat. Maybe looking at the "regulatory documentation", if it's available, would clarify what is meant - or the equivalent inspection codes in another country. $\endgroup$
    – alephzero
    Jun 18, 2016 at 0:55
  • $\begingroup$ @Air - the Russian word is шаблон, and it has dozens of possible English translations. $\endgroup$ Jun 18, 2016 at 4:35
  • $\begingroup$ @alephzero - the verbatim original is "измерительная линейка", "measuring ruler" (?). Multitran offers numerous translations $\endgroup$ Jun 18, 2016 at 4:38
  • $\begingroup$ @Air - I've added a link to the original document. I selected it to train myself in the use of industry terminology. $\endgroup$ Jun 18, 2016 at 4:42

3 Answers 3


Based on your translation of 'root face' I'm assuming that the bevel they are inspecting is a bevel that has been prepared for a groove weld between two pipes. If that's the case, the typical measurement tool, at least in America, would be a weld inspector's gauge like this one. There are various designs of gauge that do the job, but a Bridge Cam gauge is the most likely. It allows measurement of the bevel angle, the root face, and the alignment of the joint using different parts of the gauge. Under most codes, all of these are subject to inspection at the fit-up stage. It also allows measurement of assorted other things after the weld is complete, including undercut and convexity/overfill.

The part you use to measure the bevel can more generally be described as a protractor, but you wouldn't really want to tell an inspector or a welder to use a protractor. Generally a protractor refers to a larger device that is very difficult to use on thinner substrates or in tight spaces.

As for the question of pipe vs tube, I think you are correct in using 'pipe' for your application. In general american english, pipe refers to a round hollow section designed for fluid (water, air, oil, etc) to flow through. Tube refers to a hollow section that could be round, rectangular or another shape, but generally isn't designed for things to flow through it.

Do keep in mind that if the whole pipe is cut at an angle, that would be called a miter, not a bevel. A bevel specifically refers to an angled cut on the thickness of the material, in this case the thickness of the pipe wall.

More specifically in the structural fabrication world, pipe refers to a section that is manufactured in sizes corresponding to the Nominal Pipe Size standard. In this system, the pipe called 1" pipe actually has a significantly larger outside and inside diameter for historic reasons. Tube would refer to a steel section made to any other round size (usually a round number of fractional inches.)

  • $\begingroup$ Thank you! I wonder why it is called "bridge cam gauge". What is 'bridge' and what is 'cam', what do they mean.. $\endgroup$ Jun 19, 2016 at 7:58
  • $\begingroup$ Regarding pipe/tube the distinction varies with application/industry. You can purchase "pipe" for structural purposes and "tube/tubing" for flow purposes. In the chemical industry, the distinction between pipe/tube is how the size is specified and pieces joined. Pipe follows NPS (at least in the US) where the size is nominal and the thickness is set by a schedule (e.g. 40, 80, XS) whereas tube/tubing is specified by its actual outside diameter and wall thickness (e.g. 1"-083). Pipe is joined by threads or flanges whereas tubing is joined by compression fittings. Welding is possible for both. $\endgroup$
    – Byron Wall
    Jun 22, 2016 at 21:20
  • $\begingroup$ @ByronWall Yes, I think that's consistent with my last paragraph except for the fact that compression fittings are very rarely used for structural fabrication. The flow/no flow distinction is the more common one among lay-people and the NPS vs true size distinction is more common for those of us who do engineering. $\endgroup$
    – Ethan48
    Jun 22, 2016 at 21:40

Based on your translation, I think the appropriate term here is protractor. It's directly analogous to the mention of "ruler" in the preceding section, being an instrument that measures continuously in standard units rather than a tool that confirms some aspect of geometry without making an explicit measurement.

The context makes clear that the specific type of protractor would be a bevel protractor—in just the same way that "gauge" in the context of "Bevel angle inspection" refers to a bevel gauge and not, say, a gauge for gapping spark plugs. Or, since there's not really any practical difference between a bevel gauge and a bevel protractor that I'm aware, some more specialized sort of gauge designed just for pipe bevels. If I needed to routinely check pipe bevels to make sure they conformed to some set of standard offerings, I could do much worse than to use a custom set of gauges that fit on the bevel of the pipe - I'm thinking of some kind of inverted, tapered plug gauge, but I don't know that it has any more specific name. These could easily be manufactured in-house.

The important thing is that gauges are often specialized tools that classify but do not directly measure. Wire gauges are a good example—you stick the wire into holes on the instrument until you find the smallest one that it'll fit through, and then you record the gauge number marked by that hole. In the corresponding classification system, that gauge number is associated with a measurement—but the gauge doesn't actually measure continuously, it only demonstrates that the quantity you're measuring lies in between one gauge and the next.

For example, if you stick a piece of wire into your AWG tool and find that the smallest hole it fits into is the #12 hole, you can call that a 12-gauge wire—but that's not the same as measuring the diameter of the wire to be 2.053 mm (the size of a #12 gauge hole). You've only really established the diameter of the gauge hole as an upper bound, plus the diameter of the next smaller hole as a lower bound, for the actual diameter of the wire.


That mill mostly makes oil field pipe (OCTG ); at least when I visited years ago. They pretty much follow API standards which are the standards of world oil production. So you want API 5 CT, and 5 L, maybe 5C4. (Name may have changed ,but it will be same technology ). Sorry , but other answers are misleading. It may be helpful to get the GOST ( Russian spec) to compare to API to look for variations.


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