The world has a lot of different standards for a lot of things, but I have never heard of a place with the default screw thread direction being opposite.
So does each language have a fun mnemonic?
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It depends which bicycle pedal you’re screwing in. They have opposite threads, designed where they’re self tightening on each side.
Same with gas regulators that attach to the cylinders, for some reason. Oo and some hub nuts on cars
I’ve heard flammable gas uses reverse (left hand) thread to prevent cross connection. At least for welding gases in NZ; not sure about natural gas.
Acetylene does, gas lines are standard pipe.
Suppose it’s cause natural gas runs at like, 1-3 psi, while a fresh tank of acetylene is 5,000?
Least in the US
It’s also torches and everything after the regulator, which run at much lower pressure. At least in NZ
I think it might be because they’re connected and disconnected regularly so misconnection is a common problem, even with colour coding. Gas work on houses involves actually putting the fittings on pipe and is done by people who should be concentrating more on that rather than on what they’re about to weld/cut.
Exactly! Bicycle pedals have a left-hand thread on the left-hand side and “normal” threads on the right-hand side.
If I remember correctly, old timey glass kerosene lanterns also have backwards threads for some reason
Gas threads and water threads are opposites to each other for safety reasons. Might be part of that thought.
Bottlescrews and turnbuckles both have one end threaded in each direction.
Please tell Tongshen, who manufactures the popular TSDZ2 motor. The pedal keeps coming loose because they don’t do this. I keep a key on me to tighten it when it starts to loosen.
Oof, that’s some piss poor engineering right there.
And remember folks, pedal wrenches are for taking pedals off, not installing them. Except for that commenter with the e-bike.