# what is this thing? **URL:** \ **Category:** Factual Questions\ **Created:** [December 1, 2018, 10:54pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418 "2018-12-01T22:54:54Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![OldMrKnowItAll](https://avatars.discourse-cdn.com/v4/letter/o/b19c9b/32.png) [@OldMrKnowItAll](https://boards.straightdope.com/u/OldMrKnowItAll)\ **Post date:** [December 1, 2018, 10:54pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/1 "2018-12-01T22:54:54Z")
What is this and what could it be used for? I found it under my car. It looks like a big plastic screw. Could it have fallen off of something for my car? [https://i.postimg.cc/7ZMGxwz6/image3.jpg](https://postimages.org/) [https://i.postimg.cc/k5T2bsfP/image4.jpg](https://postimages.org/)[https://i.postimg.cc/WzFqjZmL/image2.jpg](https://postimages.org/)[https://i.postimg.cc/tTmnLkxN/image1.jpg](https://postimages.org/) ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [December 1, 2018, 10:59pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/2 "2018-12-01T22:59:58Z")
I really doubt it’s from an automotive application. What size is it? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [December 1, 2018, 11:04pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/3 "2018-12-01T23:04:27Z")
It looks like the screws that hold plastic trim on, like the engine covering, or stone guard. ---
**Author:** ![OldMrKnowItAll](https://avatars.discourse-cdn.com/v4/letter/o/b19c9b/32.png) [@OldMrKnowItAll](https://boards.straightdope.com/u/OldMrKnowItAll)\ **Post date:** [December 1, 2018, 11:42pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/4 "2018-12-01T23:42:13Z")
> [@Gary\_T](#): > > I really doubt it’s from an automotive application. > > What size is it? It’s pretty big for a screw. Like 3 inches ---
**Author:** ![somepumpkin](https://avatars.discourse-cdn.com/v4/letter/s/7feea3/32.png) [@somepumpkin](https://boards.straightdope.com/u/somepumpkin)\ **Post date:** [December 1, 2018, 11:52pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/5 "2018-12-01T23:52:15Z")
> [@beowulff](#): > > It looks like the screws that hold plastic trim on, like the engine covering, or stone guard. Your photo isn’t very multi-dimensional :), but [that was my thought, too](https://www.google.com/search?q=car+body+fasteners&prmd=simvn&source=lnms&tbm=isch&sa=X&ved=2ahUKEwj59ujU6P_eAhWpz4MKHW27DfMQ_AUoAnoECBkQAg&biw=1024&bih=672). (Google image search result) ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 2, 2018, 12:16am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/6 "2018-12-02T00:16:05Z")
did you find it screwed together like that? (it has two parts) ---
**Author:** ![LowSignalToNoise](https://avatars.discourse-cdn.com/v4/letter/l/ecae2f/32.png) [@LowSignalToNoise](https://boards.straightdope.com/u/LowSignalToNoise)\ **Post date:** [December 2, 2018, 12:31am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/7 "2018-12-02T00:31:34Z")
> [@beowulff](#): > > It looks like the screws that hold plastic trim on, like the engine covering, or stone guard. +1 ---
**Author:** ![Mean\_Mr.Mustard](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mean_mr.mustard/32/3865_2.png) [@Mean\_Mr.Mustard](https://boards.straightdope.com/u/Mean_Mr.Mustard)\ **Post date:** [December 2, 2018, 12:57am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/8 "2018-12-02T00:57:34Z")
> [@beowulff](#): > > It looks like the screws that hold plastic trim on, like the engine covering, or stone guard. This is the correct answer. I have seen them used in my vehicle. They are used to secure a plastic part - some sort of trim or cover - to another, also usually plastic, part. mmm ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [December 2, 2018, 2:00am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/9 "2018-12-02T02:00:21Z")
It has a slight resemblance to some automotive fasteners, but the way the two pieces fit together and most especially the size are something I’ve never seen on a car. Here’s a typical [automotive trim retainer]([http://i.ebayimg.com/00/s/MTAyNFg4MTQ=/$(KGrHqEOKpwE6VVTvq,jBOtZlDWJN!~~60\_35.JPG)](http://i.ebayimg.com/00/s/MTAyNFg4MTQ=/%24(KGrHqEOKpwE6VVTvq,jBOtZlDWJN!~~60_35.JPG)). It doesn’t measure over 3/4" (probably closer to 1/2") in either diameter or length. I find it very hard to believe that a retainer that screws together just like the one the OP showed, or one that is 3" in any dimension, much less of both that design AND of that size can be found on any automobile. ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [December 2, 2018, 2:04am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/10 "2018-12-02T02:04:45Z")
Maybe it large because it holds a big piece. Like a plastic bumper part. Or a mud flap. ETA anything hanging loose on your car? ---
**Author:** ![BobBitchin](https://avatars.discourse-cdn.com/v4/letter/b/7ea924/32.png) [@BobBitchin](https://boards.straightdope.com/u/BobBitchin)\ **Post date:** [December 2, 2018, 2:23am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/11 "2018-12-02T02:23:15Z")
Is it possibly an access plug, from the lower engine cover/shroud, for the oil drain plug? ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [December 2, 2018, 2:47am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/12 "2018-12-02T02:47:47Z")
> [@Beckdawrek](#): > > Maybe it large because it holds a big piece. Like a plastic bumper part. Or a mud flap. No, no, … > [@BobBitchin](#): > > Is it possibly an access plug, from the lower engine cover/shroud, for the oil drain plug? and no. I’ve been fixing cars professionally for over 45 years. That’s simply not the type of fastener they use. ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [December 2, 2018, 4:08am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/13 "2018-12-02T04:08:31Z")
I don’t know what it fits, but that type of fastener is called a “sex bolt”. > **[Sex bolt](https://en.wikipedia.org/wiki/Sex_bolt)** > > A sex bolt is a type of mating fastener (nut) that has a barrel-shaped flange and protruding boss that is internally threaded. The bolts sits within the components being fastened, the flange provides the bearing surface. The sex bolt and accompanying machine screw sit flush on either side of the surfaces being fastened. > It is normally chosen because of its low profile compared to other nuts. The sex bolt often has a built-in feature, such as a slot, to aid in tightening the fastener. Some sex bo... Dennis ---
**Author:** ![PatrickLondon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/patricklondon/32/4422_2.png) [@PatrickLondon](https://boards.straightdope.com/u/PatrickLondon)\ **Post date:** [December 2, 2018, 6:57am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/14 "2018-12-02T06:57:35Z")
> [@mixdenny](#): > > I don’t know what it fits, but that type of fastener is called a “sex bolt”. The mind boggles. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [December 2, 2018, 10:02am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/15 "2018-12-02T10:02:36Z")
Perhaps from another, LARGER vehicle… like a UPS truck? ---
**Author:** ![bluezooky](https://avatars.discourse-cdn.com/v4/letter/b/e8c25b/32.png) [@bluezooky](https://boards.straightdope.com/u/bluezooky)\ **Post date:** [December 2, 2018, 10:17am UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/16 "2018-12-02T10:17:43Z")
Might hold the front bonnet lining in place. ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [December 2, 2018, 2:19pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/17 "2018-12-02T14:19:42Z")
I have something similar holding down the spare tire in my trunk. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [December 2, 2018, 4:26pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/18 "2018-12-02T16:26:20Z")
Seems to be a furniture assembly bolt for DIY things. Being found under a car does not mean it is from a car. Very light weight, many ways to get under the car from a long way away. IMO ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [December 3, 2018, 10:44pm UTC](https://boards.straightdope.com/t/what-is-this-thing/825418/19 "2018-12-03T22:44:47Z")
I’ve seen those recently in toy packaging. They replace zip ties and wire ties. It’s usually when you have a heavier toy in a semi open cardboard display package.