Sport Seat belt bolt size

[Simonjjb]

Need some help...I can't seem to find the correct size bolt for the hole pictured here. The sport seat has a bolt hole on each side. The inside for the receiver works fine with a seat belt bolt that I have. But none of the bolts will take on the outside hole, the one pictured here - and I have the same issue on each seat.......Its possible it has some powder coating in the thread, but before I try that fix, can someone tell he what's the correct bolt size here? Thanks

[dirk07]

metric->M12
lenght: 14mm
SW19

[Nordschleife]

Just a guess, but if Dirk07’s M12 recommendation doesn’t fit, you might try a bolt 7/16”-20 thread pitch.

The large US auto market (and Department of Transportation safety regulations) drove auto manufacturers around the world to adopt that bolt size many years ago. It’s a funny thing, where every bolt in a German manufactured car is metric EXCEPT for the seat belt bolts, which are very often 7/16”-20.

BTW, some of these seat belt bolts for German cars have metric heads (e.g. 17mm) but the threaded portion is still 7/16”-20.

[Arne]

Even more odd, I wonder if 7/16" x 20 was selected because it is virtually interchangeable with M11x1.25. Really. Check the math.

While M11 isn't common anywhere, having a metric alternative means that automakers in metric parts of the world didn't have to buy/build non-metric tooling.

[smedley]

Need some help...I can't seem to find the correct size bolt for the hole pictured here. The sport seat has a bolt hole on each side. The inside for the receiver works fine with a seat belt bolt that I have. But none of the bolts will take on the outside hole, the one pictured here - and I have the same issue on each seat.......Its possible it has some powder coating in the thread, but before I try that fix, can someone tell he what's the correct bolt size here? Thanks

It's a DOT 7/16 fine pitch....you'll find that thread size and pitch in the belt anchors even in the tubs from '68 on. DOT mandate as of '68.

[Simonjjb]

Thanks all !

[sithot]

Just a guess, but if Dirk07’s M12 recommendation doesn’t fit, you might try a bolt 7/16”-20 thread pitch.

The large US auto market (and Department of Transportation safety regulations) drove auto manufacturers around the world to adopt that bolt size many years ago. It’s a funny thing, where every bolt in a German manufactured car is metric EXCEPT for the seat belt bolts, which are very often 7/16”-20.

BTW, some of these seat belt bolts for German cars have metric heads (e.g. 17mm) but the threaded portion is still 7/16”-20.

Yes. I've been down this road too.

[StephenAcworth]

This is why I love the Registry... where else can I follow stories like this whilst on lockdown nearly at midnight on a Monday?

[dirk07]

Sorry my fault. Too late, kids, Homeoffice,.....

Forgot to post the complete text.

7/16" UNF is the standard.
I have seen some "modified" bases with M12

[sithot]

All of $4.60 if you need to clean up the threads. Do not use a tap.