I recently bought some new fairing from China. When trying to fit the headlight to the front centre cowl, it appears that the holes for the screws are too small by a fraction. Also, in the old cowl, they have a metal fitting into which the screws are seated.

Is my new fairing a dud, or am I expected to cut my own thread into the molding?

Or should I buy some new of these metal fittings, and when they arrive, they'll actually fit and make it work by magic?

The Old Cowl

  • Notice the metal inner to where the screws are seated

old cowl old cowl

The Headlight

headlight headlight

The New Cowl

  • No metal inner, and a fraction too small

new cowl new cowl new cowl new cowl

  • 1
    I'm not sure in this case, but these may be setup to cut your own threads when upon the first time you screw the screw into it. DO NOT take my advice on this though. I've seen it the way I describe on other things, but they were actually metal parts you had to create your own threads for by using an impact to drive the screw in ... was very nerve wracking. Jun 19, 2016 at 12:04
  • 1
    Wow. You don't to get that wrong first time you do it ...
    – Stewart
    Jun 19, 2016 at 14:09
  • 2
    Exactly ... very nerve wracking. I have to say it worked out just fine, though, in my case. Jun 19, 2016 at 14:57
  • 2
    The big thing I'd be worried about in your case is it splitting it. I don't know how malleable (at all flexible) the material is. If it will deform a little, you shouldn't have any issues. If it's very resilient (hard/strong), it may split. Really a tough call from this end of the internet. Jun 19, 2016 at 20:47
  • 3
    Aaah, Chinese parts. Either tap your own threads, or drill it out and put a threaded sleeve in it. Lots of things I've had come in from ebay/China ends up quite similar. I have a rule of thumb with Chinese parts... Don't Jun 20, 2016 at 1:28

1 Answer 1


Belated answer here, to explain what I actually did in the end.

At first, I spent ages working out the technical term for those kind of screws and their housing, and I was searching all over - ebay and other places - for "Expansion Insert with Flange". I was guessing the needed size as M5.

Eventually, I found something that looked a close enough fit, and emailed the company, who quoted me £75 for 30 + postage.

30 was the minimum order. And I wasn't entirely sure they would fit or do the job.

So I gave up on that avenue, and thought I'd take a risk. I went into Halfords and bought some self-tapping screws for about £2.50 for 4.

They screwed directly into the plastic, and seem to be holding nicely. Seems I made a real meal out of such a simple solution.

Expansion Insert (Expensive) enter image description here enter image description here

Self-Tapping Screw (Cheap) enter image description here

Self-Tapping Screw Fitted enter image description here


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