Seat belt mounting
 

I am in the process of mounting new seat belts in my car. I've taken the side panels off and removed the plastic bolts that were in the holes in the picture. I measured the plastic bolts with a micrometer and came away with a measure of 10 mm diameter and 1.25 pitch. Yet, when I screwed in the bolt, it was a loose fit. I could wiggle it in the hole. The thread pitch is OK. I had the same problem with the hole in the other side. What size should these bolts be?http://forums.pelicanparts.com/uploa...1480967743.jpg

They are SAE thread 7/16-20, not metric. I have no idea why.

Wow. I never would have guessed. Maybe Porsche had to comply with some US safety dictate when imported in 1972.

This size is standardized worldwide. All seatbelt hardware uses this thread. The shoulder and head may be different for your application.

Use SAE Grade 5 bolts. Higher grades can be too brittle.

I went through the same thing years ago with the bolt on the "B" pillar. I was making a fitting so that the pillar could be attached to the roll bar, and help stiffing the structure. I could not figure out the metric thread.

I went to a Hot Rod parts store, and the counter guy said....."you sure it is not SAE?"

He said many metric cars had SAE seat belt attachments.....he was right!