i have searched around and the common size for the harness bolts seem to be 7/16 UNF.
Question is, can i use 8mm ones instead? or any other metric size for that matter?
Thanks
Whatever you use must be fine thread and have a graded mark of 8.8 for sva
which gives you a minimum of an 11mm bolt.
11mm? i think there's no such thing as an 11mm bolt. i might get 10mm or 12mm which seems a bit overkill for a seat belt.
maybe the top harness mounts would take 12mm?
and the bottom 10 or 8?
what do you think?
Cheers
On the quick release Samco harnesses they use 8mm bolts- and after seeing Mr Kubica destruction testing his harness I'd say they work okay.... I've seen a few mentions of the "7/16 or equivalent" floating around recently- is it based upon the manual or heresay? (or some SVA tester talking out of his sphincter)...
All my sva inspector checked was the 8.8 grade as I had mistakenly used two unmarked toyota ones.
I had to change them. He never removed a bolt to check.
The minimum size is 11mm it's in the SVA manual 5.2.4 Note 1.
As Nitram says they must be 8.8 grade or better. (grade S for imperial IIRC)
ok just checked the SVA manual... it says a minimum of 11mm.... or comparable strength... so does this mean if i get a 12.9 grade m8 bolt its strength
should be comparable to that of an 8.8 m12?
i'm in the process of welding the plates to the chassis and i want to get it right...
what's the common size on harnesses? 7/16?
I doubt that reasoning would work, but who knows.
Personally I'd stick with 7/16 grade S, or M12 grade 8.8 given the amount of work it would be to change later on.
http://www.tech.plym.ac.uk/sme/desnotes/boltb.htm
suggest as 8.8 11mm is stronger than a 8mm 12.9 bolt
quote:
Originally posted by BenB
http://www.tech.plym.ac.uk/sme/desnotes/boltb.htm
suggest as 8.8 11mm is stronger than a 8mm 12.9 bolt
Since an 8mm bolt has less than half the cross-sectional area of a 12mm bolt, going from 800N/mm2 to 1200N/mm2 tensile strength won't make up for
the loss in area.
For proper European type-approval the specification is that bolts must be 11.11mm dia (i.e. 7/16" ) but alternatives are allowed if they meet the
strength tests. For SVA the requirement is similar, but without the need to test.
[Edited on 21/6/07 by matt_claydon]
Mine are 12mm metric and are the Rawl eyebolts from heavy duty construction fixings. They aint marked though........maybe a fail point?
Alex