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SVA and bolt specifications
gy351100 - 23/1/09 at 07:20 PM

Hi all
Why can we not use grade "S" bolts instead of grade "8.8" as they are of the same tensile strength.
I have built my car to use UNF bolts which, as I understand, are only available in grade"S"
Metric bolts are in grade "8.8" but not all nearest equivalent sizes are compatible.

I can find no reference to grade "8.8" in the inspection manual eccept for the seat belt mounting

[Edited on 23/1/09 by gy351100]

blakep82 - 23/1/09 at 07:23 PM

i'm sure it says 'equivalent strength' doesn't it?

gy351100 - 23/1/09 at 07:27 PM

Hi
But where in the manual does it say "equivalent strength"?

blakep82 - 23/1/09 at 07:34 PM

it says
"A suitable single bolt fixing of adequate strength would be, for example a bolt of at least 11mm (7/16" diameter of grade 8.8"

fail point is a bolt of inadequate strength

it just says for example, fo find out what tensile strength an 8.8 grade metric bolt is, and then find a imperial bolt with a higher tensile strength.

or make an exception, and make your selt belt bolts metric (M12) to make it easier

James - 24/1/09 at 12:55 AM

quote:
Originally posted by gy351100
Hi all
Why can we not use grade "S" bolts instead of grade "8.8" as they are of the same tensile strength.
I have built my car to use UNF bolts which, as I understand, are only available in grade"S"
Metric bolts are in grade "8.8" but not all nearest equivalent sizes are compatible.

I can find no reference to grade "8.8" in the inspection manual eccept for the seat belt mounting

[Edited on 23/1/09 by gy351100]




Would it be a silly question to ask why you build the car this way? Is standard metric really so bad?


Cheers,
James