Petrol head thread!!!

[Dark Lightning]

I've had to be bilingual with both systems for most of my working career. The US didn't re-tool for SI units, but I spent about 20 years working with electromagnetic things, mainly antennas. Everything analytical done with them is SI until they get built and go to the antenna range- then EEU.

[Asmodean]

Interestingly, aviation is also to a large degree all feet and knots and pounds. I assume space flight is probably (mostly-) SI..?

[billy rubin]

19/32 is the real size, not the nominal size. its also 15mm.

the different grades of wrenches come with greater or lesser qualities of fit. king dick and koken are first quality, craftsman is a second quality.

a complete set of millimeter wrenches, not skipping numbers, will substitute for almost any BSF, SAE, W, or other standard AF.

[Asmodean]

I suppose some of that is by virtue of millimeters being comparatively small, no? Like, you could tighten a 14mm bolt with a 15mm wrench. This is especially true for larger sizes, but not very good for the bolts or the tools.

[billy rubin]

yes. this is not true for small bolt sizes but above about 11/16, millimeter accuracy will not damage fasteners.

the small sizes need a finer grip. my SAE sockets run in 1/16-inch steps down to about 3/8-inch, then switch to 1/32-inch steps.

even then there are different smaller standards such as BA.

thread forms are a totally different world.

[Asmodean]

Ugh! Don't I know it! My stock hardware store screws never "ever" fit the damned OEM threads I try to screw them in

[Dark Lightning]

Interestingly, aviation is also to a large degree all feet and knots and pounds. I assume space flight is probably (mostly-) SI..?

Believe it or not, EEU, and I worked on various aspects of spacecraft and aircraft for decades. I doubt that it'll ever change, just from the inertia.

[billy rubin]

see, i had to look up EEU. we re way uneven in the states

i had an odd one recently though. the boy bought a 2002 suzuki samurai. the guy he bought it from kept the old plates, but took the two screws that held it on as well. tapped holes in the metal bodywork.

no problem, i say. suzuki, so metric. so i go to the coffee can full of metric screws of various sizes and pitches.

but no. not M4 in any pitch i have.

and not 3/16 NC, not 3/16 NF, not 10-32, not 10-24, not 2BA, not anything out of my other coffee cans.

we ended up holding the tag on with bailing wire.

[Dark Lightning]

^ That's a Ford Model T fastener size.

[Icarus]

The Brits  in the past had their own way of measuring wrenches for hexagonal parts.  Whitworth sizes were determined by measuring a nut or bolt head corner to corner. Everyone else measured across the flats. 

I am glad that we have finally agreed to use the metric system for wrenches and fastener geometry. American fastener suppliers continue to sell both US sizes and metric sizes. I do not think that we have yet standardized wire and sheet metal sizes. 

[Asmodean]

Believe it or not, EEU, and I worked on various aspects of spacecraft and aircraft for decades. I doubt that it'll ever change, just from the inertia.

Really?! Cool! (Well, "cool" in the sence that The Asmo learneth, that is)

I suppose inertia is the case, yes. It's one thing to learn a new standard, it's quite another to retool "every" shop and assembly line, and even after that has been done, for all practical purposes... There are many interconnected systems at play. Documentation, software, humans, machines, tools, standards... And that's just off the very top of my  head.

[billy rubin]

the swedes decided to change from driving on the left to driving on the right. their method was to change everybody, the whole country, all at once, on the same morning.

there was mayhem

correction. my assertion that there was mayhem was based on discussions with a witness years ago. wiki tells me thar initially it went well, and that it took two years for accident levels to return to previous levels

[billy rubin]

ive just had a conversation about H day in sweden with chatgpt

chatgpt explains how sweden made the switch in order to achieve greater safety, consistent traffic patterns, and for overall smoother travel.

britain, on the other hand, maintaibs left side driving in order to achieve greater safety, consistent traffic patterns, and for overall smoother travel.

chatgpt steadfasly cites the identical determinants as favouring left side driving among the poms, but right side driving among the bark eaters

it refuses to acknowledge any logical difficult with this

[The Magic Pudding..]

Grievances:
I have a non digital speedometer that goes up to? 240km? something ridiculous.
You can suffer consequences doing 45km in a 40 zone, I'd prefer that speedometers were designed with regard to reality.

Indicators.  Left turn blink blink blink, intention to cancel, right right right, no no no I'm not turning right, I just wanted to cancel the left!

[Dark Lightning]

ive just had a conversation about H day in sweden with chatgpt

chatgpt explains how sweden made the switch in order to achieve greater safety, consistent traffic patterns, and for overall smoother travel.

britain, on the other hand, maintaibs left side driving in order to achieve greater safety, consistent traffic patterns, and for overall smoother travel.

chatgpt steadfasly cites the identical determinants as favouring left side driving among the poms, but right side driving among the bark eaters

it refuses to acknowledge any logical difficult with this

Bolding mine. chatgpt should start its own church.