---- John Reynolds <transporterjr@YAHOO.COM> wrote:
> Seat belt bolts are, for the most part, size 7/16-20 the world over - even on non-USA cars.  GM switched to M12 a number of years ago, now they have a global standard and Europe insisted it on being 7/16-20, so new GM designs will (again) be 7/16-20!
>
> The US MVSS  209(motor Vechicle Safety Spec) originally specified 1/2-20 and 7/16-20 (some early cars used 1/2-20), it now has added "or metric equivalent".  Funny thing is, US made cars had seat belt bolt standards to pass, imported cars only had to have the entire system pass, so some imports had M10 size bolts, but even cars that were never going to be made here generally used the 7/16-20 size.
>
> So what Dave says below is true - the bolts are actually 7/16-20.
>
> John -
> Who has has been involved in testing and design of "few" seat belt bolts for a few decades now.

No, the seat belt bolts are actually 11x1.25.  They ARE metric bolts, with the head marked 8.8 and some other things.  David Beierl knew this, and chastised me mildly for not knowing it, since I had the bolts right in front of me.  But, the 7/16-20 bolts fit and work -- the difference being trivial, as David Beierl stated in his last post quoted below.

Eleven mm bolts seem impossible to find locally.  I tried a large number of vendors, including the best stocked hardware store around here.  Metric bolts in even mm sizes are readily available, so both 10 and 12 mm bolts are there for the buying.  Not elevens.

> >Just so happens that 7/16-20 UNF is practically identical to
> >M11x1.25; 1% on diameter and 2% on pitch.  For a short thread
> >engagement this doesn't matter.  The UNF and ISO thread forms are
> >slightly different, but not enough to matter here.
>
> >Yours,
> >David

--
David McNeely