What is the size in "M language" of a front wheel stud, ie the hole opening on the hub, on an ami super chassis??

Can anyone help me with this....... And what's the length in mm's aswell on a standard bolt??..

Cheers
Matt

Although I've also PMed Matt covering this subject, I'll put this up here just in case other people don't understand this, but seriously it's even simpler than tyre sizes!

Firstly 'M language' is not used to measure holes, it's a system for specifying metric threads. And the size of hole you would find any specified bolt in would depend on where and how it was being used.



The specification for the thread used on a 2cv wheel stud is M12 x 1.25, ie 12mm diameter, and 1.25mm pitch(distance between teeth). It doesn't tell us anything else about the stud. In this case the hole in the hub is 16mm as the stud is 'shouldered', in that it has a thicker section under the head, but this is unrelated to the size of the thread.
I don't know the stud length off hand but can measure it in the morning.

the "M" bit is the size of the hole through which the bolt passes so a M12 passes through a 12mm hole* but as Jools points out its not as easy as that

( *bolt geometry for the Iphone generation)

The stud length is 27mm, measured to the underside of the head, as is standard for any type of fixings other than those with a coutersunk head.

I've even found a picture for you showing the shoulder,

cool! brass wheel studs that'll save having to get the AA out to stuck nuts

but now the giddyness has gone, matt what are you trying to do?

if you have an ami front rotor with damaged studs im pretty certain the rear studs are the same and can be driven out a scrap drum the fronts are held in with a mig blob so the angle grinder is required

Well.........

As you can probably c or if u have read me thread, I have GS alloys fitted all round, they fit fine on the back (well they just clear the wings by a couple of mm)
Anyway as someone (me) has lowered it a bit and fitted 155 tyres, when on almost full lock the tyre rubs the exhaust on the near side and the suspension arm on the off side.....
So I thought why raise it back up a few inches and probably solve the problem, when i can leave it as it is and cause myself more problems
so i'll need some spacers, which joolz is hopefully going to get sorted for me soon, once they are fitted i will have to get some longer studs as I've got about 20mm to take into account...

My task now is to try and source a matching stud, well 6 which r about 20mm longer