when/where was the “left = open/loosen, right = close/tighten” standard created? are there any bottles or containers around today where you have to turn the lid clockwise to open it?
Not a container but the left hand pedal on bicycle are a reverse thread.
This is the sort of thing that never became formalized until long after people had developed an informal standard. That probably happened when some guy started selling thread-cutting tools, which saved everybody else from having to make their own (Whitworth, I suppose). It also resulted in many individuals coming up with their own thread design and count. Trust me, you really don’t want to dig too deeply into that, unless you own an older British sports car and have only an Ace Hardware to supply your fasteners.
Even ignoring Whitworth threads, the search at Ace for a wing nut took me from a 19-cent item to to one that cost me $3.50, a tenth of the cost of the original fan. (Found the original fastener yesterday, two years too late.)
Some reactive gases come in tanks with the opposite convention on the nozzles, so you can’t accidentally hook them up to a hose that’s not rated for them.
The advent of interchangeable standardized parts came with the mass manufacture of firearms. I’ll bet that’s when the thread direction convention was adopted.
I’ve known oxygen charging bottles to have the clockwise = undo convention when used on replenishing aircraft oxygen systems. This is to prevent charging the system with an incorrect gas e.g. nitrogen.
Whitworth developed the first thread standard, before that people cut threads to their own private standard or individually, as anyone who tries to restore an old steam engine soon discovers.
It’s easy to see why. Most people are right-handed. The important thing is to get bolts tightened up - it’s some other poor sod’s problem to undo them! The most pressure will go in the natural direction of rotation. In a lot of cases the thread is on something that in normal use comes under rotation and normal rotation will be clockwise, so you want to avoid anything that might tend to untighten bolts.
It’s another piece of the Right Hand Conspiracy.
From an ergonomic standpoint, a right handed person has more power to drive a screw turning clockwise. It doesn’t usually take as much force to pull a screw out.
As an experiment, use your left hand to drive a screw into a piece of wood without boring a hole first. It’s a lot harder, isn’t it? Most left handed carpenters hold the screwdriver like an ice pick when they need more power.
ETA: Jerseyman gets there first, the swine. That’ll teach me to look for evidence…
'Tis a bugger because I’m sort of ambidextrous - different hands for different things and for delicate work like starting a screw off (be careful how I phrase that!) or removing it I’m likely to be left-handed but if it needs the real power stuff, finish it off with the right. Then again I’ve known people who swear by if it’s going straight into wood, hammering it halfway and only screwing it at the end. They probably put all the screws in that never come out agan because they’re bent and the head sheers off :rolleyes:
I’ve done a fair amount of recharging aircraft oxygen systems, but not yet encountered a left-hand thread. It is true that essentially all gas bottles have a thread unique to that gas type.
I had an old Chrysler that had one side with left handed threads on the wheels.
Chrysler products built prior to 1949 all used lug studs instead of separate lug nuts and wheel studs to hold the wheels on. The lug studs were right hand threads on the right side of the car and left hand thread on the left side of the car, they did this because right handed lug studs had a tendency to loosen when placed on the left side of motor vehicles. Chrysler carried over the left handed threads on lug nuts and wheel studs till 1970, Chrysler finally figured out what every other car manufacturer had known, right handed threaded lug nuts did not have the tendency to loosen like lug studs.
In 1979 I owned a 1969 Dodge Coronet. I found myself needed new tires while traveling between San Diego and Tacoma, Washington and stopped at a gas station just off I-5 in Salem, Oregon. The owner of the shop raised up the car on his lift and told a kid working for him to take the wheels off my car so he could install 4 new tires. I take off up the street to find something to eat. I returned about 40 minutes later, the and find the owner of the shop pulling the left rear axle from my car. I also notice my left front hub and brake drum are off. The kid had busted off a bunch of studs on the left side, he tightened them till they broke. The owner replaced all 10 studs and lug nuts, installed 4 new tires and I was on my way in about an hour.
Right, I think propane for the gas grill and probably indoor nat gas connections have these.
Dirty joke:
The legend of Curly Dick
He was a man with a corkscrew prick
Spent his life in a relentless hunt
Searching for a woman with a corkscrew cunt
When he finally found her, he nearly dropped dead
That dirty ol’ bitch had a left hand thread.
hahaha. Am I the only one who saw the thread title and thought that you got tired of the way threads were going, and made a thread about that?
True that, also old British sports cars with wire wheels, the knock off were different threads on the two sides of the car.
It’s because of the old “centripetal force tightening the lugnuts as you drive” thing, right?
So I have been told.
I think it has more to do with angular momentum/inertia than with centripetal force.
It goes the opposite way in the southern hemisphere.