Not afraid to ask an amazingly dumb question.
 

Are all the bolts, nuts, etc. on a 911 metric?

Yes, it's a "duh" kind of question.

Thanks on advance.

Lawrence

They should all be, even the ones sold in the UK! :D

They should be, but my negative battery post nut is 1/2 inch as are the bolts securing my AC compressor to the base.

NO, not all the bolts in a Porsche are metric.
There is a bolt that is not metric

Check the seat belt bolts 7/16 fine thread.

I think it is a worldwide standard.

US specific stuff sometimes are not metric, at least the heads are us but the threads might be metric. but that's only government mandated safety crap. Ether that or the bolt heads shrank and my metric wrenches won't fit.
Remember, there are no silly questions, just silly people!!!

The heads can be metric but the threads are 7/16 for seat belts.
I have Schroth belts , the heads are metric and the threads are 7/16.

13mm and 1/2 inch are really, really close in size. Almost interchangeable.:)

Yeah, but my 13mm seemed kinda loose and the 1/2 inch fit like a glove. :)

Yes - seat belt posts are 7/16 -20 thread - porsche put 17mm heads on them - most likely be 5/8 if you pick them up at the autoparts store.

Brake bolt spacing is either 3" or 3.5' brake bleeder screws are usually 3/8 or 7/16

Seat belts are 2". Tire sizes are inches then aspect ratios. Gas filler caps are 1 1/4 or 1 1/2 or something like that. There are a few more but I've been asleep since I had this discussion over beers a few years ago.

Really, really close is 19mm and 3/4".... difference being 0.05mm

I worked on a late 80's Ford Mustang several months ago... what a mixture of fasteners... I spent more time figuring out which wrench was corrent than actually turning them! :mad:

And the wheels are measured in inches. Diameter & width.

A/C hoses are all US thread.......