'Course, I’ve always wondered why turning something in a clockwise direction meant that you were turning something to the right. It’s a circular motion, after all, and while the top part appears to be moving to the right, the bottom part is moving toward the left. In fact, often, when working with nuts or bolts that have to be loosened, one finds oneself with the wrench in hand, pushing to the left, in order to loosen said nut or bolt. I understand that it’s a grand thing that screw threads are standardized, but the right/left thing always perplexes me.
Also, apropos of one of the posts, I remember trying to change tires and having a hell of a time loosening the lugnuts, until I realized that they were threaded in the reverse direction. I don’t know if that’s still the case, and as someone suggested, it only occurred on one side of the automobile - which I never noticed, anyway. I probably tightened up some lugnuts REAL tight before I realized I had to go the other way. xo, C.
Oh, crap, I meant to say **right ** But you get my point, I hope. :smack:
That’s not an answer. It’s just another mnemonic to go alongside the one in the thread title.
I was going to post the exact same thing. I remember my first encounter with the phrase “righty tighty, lefty loosie”, and it took a while to explain to me. “To make it tight, turn to the right!” Me: “ehhh…turn WHAT to the right? shouldn’t I be rotating something either clockwise or counter-clockwise?”
–KidScruffy
However, regardless where we place or how we apply a wrench, we generall look at the top of the circle being turned. Whether it is circular faucet handles, doorknobs, or steamboat wheels, the top is how we generally reckon the direction.
(Of course, faucet handles that extend back toward the sink and some other devices–wrenches placed on nuts from below–are going to mess up any clean analogies, but I suspect that it is still more common to view the direction we call clockwise as “turning right.” Even the hands on the clock (or the gnomon shadows that probably initially suggested their direction) seem to move from right to left–i.e., “turning right.”)
One esoteric excuse for the normal thread being called right hand is its appearance. When you look down at a right hand screw thread, the right hand side leads the left.
So there.
A friend of mine in high school had a similar problem when he was learning to drive. He couldn’t understand that pushing UP on the blinker stalk made the right blinker come on and vice-versa.
Now I notice that lately, Ford is putting the turn signal stalk at almost the 11:00 position to where you’re pretty much moving it right or left to turn on the blinkers.
I believe the left hand threads were on the driver’s side. I, too, was perplexed by this on my 1969 Dodge Charger. I have since replaced the lugs so they are all “normal.” But if I ever bring the car to a shop, I have to tell them that I replaced the lugs, because otherwise they may expect them to be 1969 “Chrysler correct.”
I believe the theory was that the lugnuts would be less likely to loosen due to the rotation of the wheel.
One left-hand thread holdout is the inside nut which fixes a toilet flush handle assembly to the tank. Some manufacturers use RH threads, but the majority are LH.
as noted previously it was the driver’s side and led to one of the few really funny practical jokes I’ve heard of.
There was an crabby, old guy who loved on our block when I was growing up. Some of the older guys got a right-hand lug nut. Then one dark night they removed one of the left-hand lug nuts from a wheel, dropped the right-hand nut in the hub cap and put the cap back on the wheel.
When the guy started out the loose nut made a noise, so he stopped and looked around. He didn’t see anything so he started up again. Again the noise started. He finally discovered the loose nut and saw an emptly lug. He spent considerable time trying to get the nut to go on the lug, finally gave up, drove off slowly and presumeably took it to a garage.
I trust someone notified the authorities. 
Some types of rotating machinery use left hand threads. A standard circular saw uses a right hand thread for the bolt that secures the blade. The blade spins counterclockwise, the bolt tightens clockwise.
A “worm-drive” circ saw is the opposite. Left hand thread for the bolt, clockwise rotation. This decreases the chance of the blade loosening. You may have noticed this while using a cordless drill with a chuck you hand tighten. That’s why the chuck sometimes loosens when the drill is reversed. You basically want the direction of tightening opposite of the direction of rotation. I hope that is confusing enough.
Also, most welding/cutting torches have left hand threads for the fuel gas and right for the oxygen. This avoids dangerous confusion issues.
Ageism, ageism. Since when is it illegal for old, crabby guys (if that isn’t an unecessary redundancey) to love?
I’m not so sure.
Because it seems to be so universal* that clockwise=tighter in all such threaded fasteners (bolts, screws, etc.), even though they were developed in cultures all over the world. So presumably there is a reason all these different cultures end up standardizing on right-hand threads, and the prevalence of right-handedness seems a reasonable explanation.
- My original ‘cite’ for this is a long-ago college discussion where an engineering student reported this. It was supported by an anthropology (?) student, who said that even primitive cultures attached stone spearheads to wooden sticks with vines wound clockwise, and that there were ancient wells in the Middle East, where the water bucket pulley rotated clockwise.
You know the right hand rule is just as much an arbitrary standard as the righty-tighty rule, right? Furthermore I’d like a cite for the fact that the right hand rule in physics in any way influenced screws to be threaded right-handed, because I think that “righty-tighty” predates the right hand rule.
Yes it is the correct answer, because the people who made the first screw threads were engineers, and they deliberately designed them to conform to the right-hand rule.
I really hope you’re whooshing.
A thought: weren’t Archimedes Screws among the earliest uses of a spiral thread? And with these, isn’t the top of the screw the most likely to be easily visible? So if rotation clockwise, the top would be moving right, and vice versa.
Perhaps I didn’t make it clear that the right-hand rule was a rule of physics long before there were screw threads.
And I hope you’re whooshing if you think Archimedes said “righty-tighty, lefty-loosy”. 
Prove me wrong 