Suspension bolts grading

[rotoflex]

What grade bolts should be used in the suspension?

I'm looking at a set of bolts for a front suspension rebuild that are advertised as Grade 5.  

[RedRooster]

That would be grade 5.5, a pretty low grade, 8.8 is better at EN20 with 12.8 being the equivilent of EN40 i believe.
RR

[That Man]

Grade 5 is the equivalent to 8.8 Metric, so i would say that's ok. But there's not harm in going higher.

Gordon

[RedRooster]

That_Man wrote:

Grade 5 is the equivalent to 8.8 Metric, so i would say that's ok. But there's not harm in going higher.

Gordon

8.8 is lowest grade i would use on suspension, it all depends where the fastener is & the load it sees if you need to go to a 12.8.
RR

[black6osprey]

American grade 5 ie metric 8.8, is a pretty normal spec for a suspension bolt. If you want to over engineer the whole thing like most people seem to be obsessed with doing then go for it and use a higher grade but unless your planning on serious track use I really wouldn't bother.

[drofgum]

Bill,
As the others have said the grade 5 bolts should be fine. That is the grade that Triumph used when they built the car. A caution about grade 8 bolts; though they have a higher tensile strength, they are more sensitive to notch damage failure in shear applications. The racer's rule of "turn the nut, not the bolt" has greater importance with grade 8 fasteners than with grade 5.
                                                                        Cheers,
                                                                        Paul

[rotoflex]

Thanks all!