Thread: What grade bolts to mount seats

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I am getting ready to mount new seats in my Studebaker. These are seats from a Chrysler Sebring convertible that have integral 3 point belts. The mounting needs to be able to stand up to g-forces associated with seat belt anchoring. My floor is re-enforced and plenty strong to bolt the seats. Next question is what grade bolts to use. Is grade 5 adequate or should I spring for the grade 8s?

Most of the bolts will be clamping force, but a couple will have side stress.

thanks

Pat

The cost between 5 and 8 is minimal but the performance gap is vast.

Just because I overbuild everything, I use grade 8's almost exclusively. As Richard said, the cost difference is minimal and they have a nice gold coating on them that lasts pretty well too. Grade 5 would probably be more than adequate but better to err on the side of overkill.


Don

Thanks guys, kinda what I figured.

Pat

I'm with Don and Tech. I'd use grade 8 just for, if nothing else, peace of mind.

Grade 8 is an overkill but there's no down side to it either..

Grade 8 is a bit more than needed but I use Grade 8 on pretty much everything. I am one to overdo everything and I act like I have OCD on things like this and need/want everything to be perfect. Plus like Don mentioned they have the gold coating and help from corrosion. On my 66 F100 I used big grade 8's (cannot remember the size right now) and used big washers underneath as to not have them pull through the sheet metal.

Mine are 3/8" Gr-8. The seat belt bolts are also Gr-8. I don't relish meeting the windshield with my face, nor the steering column with my (beer) belly

Originally Posted by IC2

.........nor the steering column with my (beer) belly

Oh, I thought that worked like airbags.


Don

Grade 8.... As stated above, some say its over kill but I tend to do that when my life comes into the equation. I would also use a grade 8 washer on both inside and outside of the car also. The washers will help spread the load of said "g forces" over a wider area so the bolt head does not pull through the thin sheet metal as easily.

Originally Posted by Itoldyouso

Oh, I thought that worked like airbags.


Don

Hrummmmph. I worked long and hard to attain my figure - and want nothing to harm that "perfection"

As a side note

Using grade 8 bolts will in some cases allow you to use smaller sizes , thusly saving weight

Farm & Fleet sell grade 8 in bulk by weight, so if your near something similar you can buy all your nuts and washers plus several more commonly used bolts for what just a few would cost at a hard ware store

And an airbag is lighter than a beer belly for crash protection so use the grade 8.

Originally Posted by jerry clayton

As a side note

Using grade 8 bolts will in some cases allow you to use smaller sizes , thusly saving weight

Farm & Fleet sell grade 8 in bulk by weight, so if your near something similar you can buy all your nuts and washers plus several more commonly used bolts for what just a few would cost at a hard ware store

And an airbag is lighter than a beer belly for crash protection so use the grade 8.

Only a racer would figure light weight into it, good one....

Originally Posted by jerry clayton

As a side note

Using grade 8 bolts will in some cases allow you to use smaller sizes , thusly saving weight

Farm & Fleet sell grade 8 in bulk by weight, so if your near something similar you can buy all your nuts and washers plus several more commonly used bolts for what just a few would cost at a hard ware store

And an airbag is lighter than a beer belly for crash protection so use the grade 8.

hmmmm. You saying Dave has a Grade 8 Beer Belly?????