A progressing cavity pump is sometimes referred to as an eccentric screw pump, because it features a screw that turns abound an axis other than its center. 'Eccentric screw pump' yields many Google hits, while professionals seem to use the term 'PC pump'.

The German term would be Exzenterschneckenpumpe, so to me and to other Germans it may come naturally to translate this verbatim and arrive at eccentric screw pump. But 'eccentric screw' might also sound like a sex act. Does the term 'eccentric screw pump' have sexual connotaions to a native English speaker?

  • Some. But I'd say the term doesn't sound as outlandish as 'progressing cavity pump'. Jan 31, 2014 at 10:45
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    Probably no more than such as 'male and female threads'. It might be fun to compile a list of embarrassing engineering terms! I bet there would be a good page full.
    – WS2
    Jan 31, 2014 at 12:06

2 Answers 2


I'd say "yes" to "weird association" and "no" to "sexual connotations".

I don't think sex is particularly weird, though certainly if the sex you were having was an eccentric screw, I suppose that would be weird by definition.

The sense of eccentric referring to people who act weirdly, (applied to anything from mildly unusual habits through to severe but physically non-threatening mental problems) might be one reason to avoid the term, and would also lead to screw being more likely to be misread as referring to weird behaviour (c.f. screw-ball, screwy) than in a sexual sense.

That may have led to people preferring other terms that don't use eccentric, though it's hard to judge how much that was an influence and how much other factors are; progressive cavity pump is a good description of how it works, after all.


It might. However, you should consider that this is fairly specific terminology and consider where the phrase is going to be used. People who know or should know what an eccentric screw pump is should not see the usage of the term as weird. On the other hand, people who have no idea what you are talking about and have no interest in such details should probably be spared said details.

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