# Righty-loosey, lefty-tighty **URL:** \ **Category:** Factual Questions\ **Created:** [May 22, 2011, 4:46am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756 "2011-05-22T04:46:28Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [May 23, 2011, 1:00am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/41 "2011-05-23T01:00:49Z")
> [@Der\_Trihs](#): > > I read years ago (can’t find a cite though) that some of the Nazis more secret weapons had anti-tampering devices that consisted of reverse threaded bolts or screws, a bracket, and a glass flask of poison gas. If the screws were turned the wrong way (which would be the right way for normal fasteners of course), the bracket would be bent and shatter the glass flask releasing the poison gas. I don’t believe this. First of all, what Nazi Secret Weapons? As far as I know, there were only 2 major ones: V-1/V-2 rockets and jet engines. And neither of them are likely to need anti-tampering devices. The V-rockets blew up when they reached England, so nothing was left to ‘tamper’ with. And the jet engines were on planes – if they came down over Allied territory, it was usually in a ‘crash’, and again there wouldn’t be enough left to worry about ‘tampering’ with it. ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [May 24, 2011, 4:46am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/42 "2011-05-24T04:46:45Z")
> [@hibernicus](#): > > Consider a person running around the block. If she is running clockwise, she will make 4 right turns. If she is running clockwise in a circle, she will be turning right continuously. If she is standing on a (very large) nut that is being turned clockwise using an enormous wrench, she will experience this as being turned to the right. This had confused me, too. Your explanation is clear and makes perfect sense. But do people who use it really think this, or have they just memorized “right” to describe the movement of the screw? > [@](#): > > This terminology is used in aviation. If a pilot is flying a clockwise pattern (circuit), this is called a “right-hand circuit”, because all of the turns are right turns. But they really are making right turns from their own perspective. The analogous situation would be to have it termed it a “clockwise” circuit. > [@](#): > > So the relationship between “clockwise” and “right” is very natural. Personally, I don’t think it’s “natural” for me to visualize a different physical perspective instead of using an existing common word that describes the action without that shift in perspective. ---
**Author:** ![RandMcnally](https://avatars.discourse-cdn.com/v4/letter/r/b782af/32.png) [@RandMcnally](https://boards.straightdope.com/u/RandMcnally)\ **Post date:** [May 24, 2011, 6:02am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/43 "2011-05-24T06:02:17Z")
> [@AlsoNamedBort](#): > > I meant why did they decide right over left. Flip a coin? Because “righty-loosy” is just plain weird. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [May 24, 2011, 8:47pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/44 "2011-05-24T20:47:33Z")
> [@t-bonham@scc.net](#): > > I don’t believe this. > > First of all, what Nazi Secret Weapons? > > As far as I know, there were only 2 major ones: V-1/V-2 rockets and jet engines. And neither of them are likely to need anti-tampering devices. The V-rockets blew up when they reached England, so nothing was left to ‘tamper’ with. And the jet engines were on planes – if they came down over Allied territory, it was usually in a ‘crash’, and again there wouldn’t be enough left to worry about ‘tampering’ with it. I am doubtful too. The Nazis were plenty evil, but they weren’t the type to dip a henchman’s face in acid just because he mispronounced Goebbel’s name. They were fascists, not James Bond villains. I don’t think they were going to risk a highly-trained technician’s life, just because he had too many kirschwassers at lunch and confused the directions of the threads. Another place I have seen backwards threads is on the bolt that holds the pad on on a floor buffer. Presumably for the same reasons as the bike pedal. The above mentioned Lada makes me think: are CC threads more common in Russia and Japan and places like that? Just seems I notice it in their products more often (which isn’t that often). ---
**Author:** ![Kiwi\_Fruit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kiwi_fruit/32/12_2.png) [@Kiwi\_Fruit](https://boards.straightdope.com/u/Kiwi_Fruit)\ **Post date:** [May 25, 2011, 1:24am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/45 "2011-05-25T01:24:11Z")
> [@GreasyJack](#): > > Some older Chryslers had left hand thread lug nuts on the left side of the car, also for a similar reason that the rotation of the wheels could theoretically loosen the nuts. I remember my father’s car, a 1965 Chrysler Valiant, had this. There was an ‘L’ stamped on the end of the stud to remind you, but it’s something that’s hard to see at night, in pouring rain and freezing cold! ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [May 25, 2011, 2:41am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/46 "2011-05-25T02:41:08Z")
I believe it was the Brush brand auto that had an engine that turned the opposite way of most other cars. I winder if it was richer in left hand threads? ---
**Author:** ![Ponch8](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ponch8/32/9883_2.png) [@Ponch8](https://boards.straightdope.com/u/Ponch8)\ **Post date:** [May 25, 2011, 2:59am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/47 "2011-05-25T02:59:28Z")
There’s a brand of camera (I believe it’s Olympus) where the lenses have reverse threads. ---
**Author:** ![Mama\_Zappa](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@Mama\_Zappa](https://boards.straightdope.com/u/Mama_Zappa)\ **Post date:** [May 25, 2011, 8:07pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/48 "2011-05-25T20:07:03Z")
One of the attachments for our former gas grill was left-handed. I don’t remember which one; might have been the thing that attaches from the grill to the cylinder (in which case I guess it’s that way on the new one also). IIRC, when we first noticed this, it was after a few minutes of increasing frustration! ---
**Author:** ![Saltire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saltire/32/553_2.png) [@Saltire](https://boards.straightdope.com/u/Saltire)\ **Post date:** [May 25, 2011, 8:34pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/49 "2011-05-25T20:34:56Z")
Another way of picturing why clockwise is right-handed is that if you imagine wrapping the fingers of your right hand around the bolt, turning the nut in the direction toward your fingertips will move it in the direction of your thumb. Left-hand thread is the same way, only with the other hand. Of course, right-hand toward your thumb is counterclockwise, but that’s for loosening. Go the other way to tighten. ---
**Author:** ![mlees](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@mlees](https://boards.straightdope.com/u/mlees)\ **Post date:** [May 25, 2011, 9:13pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/50 "2011-05-25T21:13:56Z")
> [@t-bonham@scc.net](#): > > I don’t believe this. > > First of all, what Nazi Secret Weapons? > > As far as I know, there were only 2 major ones: V-1/V-2 rockets and jet engines. And neither of them are likely to need anti-tampering devices. The V-rockets blew up when they reached England, so nothing was left to ‘tamper’ with. And the jet engines were on planes – if they came down over Allied territory, it was usually in a ‘crash’, and again there wouldn’t be enough left to worry about ‘tampering’ with it. Speculation: The only thing I could think of might be something like the magnetic naval mines, or time delayed bombs, air-dropped into enemy territory. You might make your screws non-standard, just to make it tougher on a bomb disposal specialist. But I don’t know if that (reverse screw) was ever actually ever done. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [May 25, 2011, 9:51pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/51 "2011-05-25T21:51:31Z")
Another common item with left-handed threads is the nut that holds an edger blade on. Same reason as a left bike pedal. By the way, the “lefty-loosey righty-tighty” mnemonic is useless in my opinion, because it’s not at all obvious which circular direction is meant by “left” or “right.” Anyone who doesn’t know which direction is the standard for tightening or loosening a screw isn’t going to benefit from the saying. ---
**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:** [May 26, 2011, 3:51pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/52 "2011-05-26T15:51:17Z")
> [@yabob](#): > > International Scouts, at least during a certain period, had left handed lug nuts on one side, so International Harvester did it as well as Chrysler. What about pre-Chrysler Jeeps? Perhaps this is a feature of a contracted supplier such as Dana. [http://www.dana.com/wps/wcm/connect/dext/Dana/Home](http://www.dana.com/wps/wcm/connect/dext/Dana/Home) ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [May 26, 2011, 5:19pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/53 "2011-05-26T17:19:40Z")
> [@friedo](#): > > Here’s a weird example: there used to be a problem with people sneaking into NYC subway tunnels and stealing light bulbs. So they started replacing all the fixtures with reverse-threaded sockets that took reverse-threaded bulbs that could only be ordered in bulk. That successfully deterred people from stealing them, at the cost of significantly more expensive custom light bulbs. Wow. People are assholes. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [May 28, 2011, 9:30am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/54 "2011-05-28T09:30:34Z")
I most commonly see reverse threads on fans, those desk/standing fans with removable blades and grills. ---
**Author:** ![panamajack](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@panamajack](https://boards.straightdope.com/u/panamajack)\ **Post date:** [May 28, 2011, 9:37pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/55 "2011-05-28T21:37:29Z")
> [@rowrrbazzle](#): > > The analogous situation would be to have it termed it a “clockwise” circuit. In that particular case, the difficulty in using that term is more obvious - viewed from the ground, a right-hand circuit is not clockwise. I’ve run into problems with people when trying to refer to something situated between us while we were facing each other. Sticking with the perspective of the moving object is a sensible way to reduce confusion. ---
**Author:** ![stanger](https://avatars.discourse-cdn.com/v4/letter/s/7ba0ec/32.png) [@stanger](https://boards.straightdope.com/u/stanger)\ **Post date:** [May 28, 2011, 11:50pm UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/56 "2011-05-28T23:50:24Z")
If anyone has a small bench grinder in their garage (you know, the one that has grinding wheels on it, or maybe one is a circular wire brush), you will find that the left side wheel is held on by LH threads. This is so the resistance you put on the wheel by using it doesn’t cause the nut to back off and the wheel to come off. Many motor driven appliances are this way for the same reason. ---
**Author:** ![Ruby](https://avatars.discourse-cdn.com/v4/letter/r/13edae/32.png) [@Ruby](https://boards.straightdope.com/u/Ruby)\ **Post date:** [May 29, 2011, 12:56am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/57 "2011-05-29T00:56:34Z")
> [@Measure\_for\_Measure](#): > > I once saw a guy struggle with some sort of screw on a Soviet vintage [Lada](http://en.wikipedia.org/wiki/Lada) for 20 minutes (to adjust the seat, if you care) before he discovered that the threads were reversed. > [@Chefguy](#): > > The flush handle on your toilet is left-threaded. I watched a plumber crack my toilet by forgetting that little fact. > [@Rysdad](#): > > Found out the hard way when I tried to change a left front flat on my '56 Pontiac. Wrestled with it for a while, then I seemed to vaguely remember backward threads…sure 'nuff, it worked. Which begs the question, why in hell can’t the reverse threads be marked somehow so that the user KNOWS not to righty-tighty with the potential for major damage. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [May 29, 2011, 1:17am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/58 "2011-05-29T01:17:44Z")
> [@Ruby](#): > > Which begs the question, why in hell can’t the reverse threads be marked somehow so that the user KNOWS not to righty-tighty with the potential for major damage. in the case of my truck, the ends of the studs were marked with an “L” but years of grime and surface rust made it, er, not so easy to see. ---
**Author:** ![Ruby](https://avatars.discourse-cdn.com/v4/letter/r/13edae/32.png) [@Ruby](https://boards.straightdope.com/u/Ruby)\ **Post date:** [May 29, 2011, 5:00am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/59 "2011-05-29T05:00:03Z")
That only makes sense to me. Every time I get a nut that won’t break loose I worry that it’s left-threaded and the only thing I’m accomplishing is making it tighter. Maybe I’ll start a campaign to require manufacturers to make all left threaded things in pink. That’ll fix it fer sher. ---
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [May 29, 2011, 6:06am UTC](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756/60 "2011-05-29T06:06:21Z")
random, but our viscometers have reverse threading for the attachment spindles which are screw-threaded. We grilled the sales rep (jokingly) about this the last time when he was here and he just laughed and threw his hands up in the air. “The founder was a bit eccentric” [Previous page](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756.md?page=2) [Next page](https://boards.straightdope.com/t/righty-loosey-lefty-tighty/582756.md?page=4)