On my sliding patio screen door there is an height adjuster held in place by flat-profile screw inserts. I'd like to obtain more of these threaded bolts and inserts, but I have a nomenclature issue where I can't identify them precisely.

sliding adjuster The bottom and top rails of the frame allow sliding up and down to adjust the overall height of the door. The height setting is locked with a phillips-head bolt and screwed insert which looks like a rivet. this is the back view.

front back

What type of screw is that?

It looks like the insert for a rivet nut (rivnut), but the lip is larger. I could assemble something like it with rivnuts, but I'd need to buy the corresponding crimping tool.

It could be a Chicago screw post (used to bind leather pieces or photo album books), but I've not been able to find any Chicago screw posts that are of matching dimensions and material (I'd need M4-9mm screw with 10mm insert). If there is a generic name that captures both rivnuts and chicago posts, I don't know it.

Any fastener which is slim would probably work (the frame needs to be as thin as possible to slide freely around the glass panel frame). I'll probably just end up using a slim nut and bolt cut to length if I can't find out what it is.

  • Since this just bubbled to the top, a comment for future readers: While the original "binding post" or "sex bolt" may have been an M4-9mm, I'm not entirely sure that the replacement would need to be that exact size. So long as the length is long enough to reach and short enough to clear when the door slides, I don't really think metric v SAE threads or thread pitch would have any impact on the replacement piece. Just thinking out loud...
    – FreeMan
    May 29, 2020 at 13:16

3 Answers 3


They are most often called a "binding post", at least that is what the fastener suppliers in the U.S. generally sell them as. I have heard people call them "Chicago nuts" but not often.

enter image description here

As a side note, those adjustable sliding screen doors are difficult to make work properly and of poor quality. Do yourself a favor and get a custom made heavy duty door, with a frame made of extruded aluminum. They are worth the investment over the long haul, provided they are sized correctly and installed and maintained properly. At least that has been my experience.

  • 1
    I do find some hits with those terms, but I'll have to dig to find the sizes I need. looks like a rare size. re: side note, it's for an apartment so not sure about the long haul. it's definitely a compromise - the step down was a magnetic screen curtain the step up was a custom design and installation. I generally agree, I get what I pay for. the question is more about the screw than its application, but I felt if I gave some context it would improve the chances of having the question be useful to others. "identify this" answers are hard to find without any context.
    – init_js
    Jun 23, 2018 at 0:18
  • Agreed, my comment was meant to help in case you had a chance of returning. Try a good hardware store, I used to carry a selection of various lengths and diameters, along with screws, in a couple flat assortment boxes in the fastener dept. Jun 23, 2018 at 2:18
  • I call them "Chicago screws".
    – MackM
    Jan 13, 2023 at 21:39

I too have the same problem with my cheap screen door. I believe I might be able to fix it with a sex bolt (which the actual name for the hardware).

  • Google "Binding barrels" or "barrel nuts" Here's a whole bunch of them to pick from
    – gnicko
    May 29, 2020 at 17:34

Try "connector screw", "knockdown bolt", or "cap nut".

  • ooh. good. knockdown bolts are generally much bigger and have some sort of lock cylinder. connector cap nut and connector screw get me some more results. M4 screw size is definitely harder to find -- 1/4" seems much more common. Might have to visit a few hardware stores.
    – init_js
    Jun 22, 2018 at 6:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.