Stainless suspension bolts.

[Stuck]

To cut a long story short I'm rebuilding the suspension on my dual axle boat trailer. Is there any reason that I shouldn't use stainless bolts through the spring eyes and the "rocker box" pivot.

Cheers,
Anthony.

[ramblingboy42]

stainless steel suffers stress fractures.....there is also quite a variety of different ss available , one which MAY be suitable, but I doubt if you can get bolts made from it. there is a hi-tensile ss bolt available, but I wouldnt trust it in suspensions. I work with ss a fair bit and its amazing how it fractures. seek further advice.

[isuzurover]

Bush65 is the expert on bolts and bolted joints on here. I would ask him.

[100inch]

No stainless bolts on suspension, cages, towbars or whatever. Has to do with differences in tensile-ductile behavior to C-steel.cheers marc

[Didge]

What's C steel? Sorry to be ignorant :)

[Slunnie]

Carbon steel. - normal steel without additional special alloys.

[JDNSW]

Most stainless steel (Including all the types used in commercial fasteners) is subject to work hardening, where cyclic stresses eventually cause hardening, cracking and failure. For this reason it is an unsuitable material to use anywhere in a vehicle or trailer suspension.

John

[Bigbjorn]

"Stainless steel" is a registered trade name for a cutlery steel which has been corrupted into common use as a term for chromium, and chromium-nickel alloy steels. "Stainless" steel fasteners should never be used in an application requiring a high tensile bolt. For non-critical items, fine, such as holding on body panels and accessories. If the application calls for SAE Grade 5 or 8, use them.

In recent years it has become a favourite with restorers whose infrequent use of their toy results in rusty bolts and nuts from storage so they go for stainless fasteners. Stainless steels are the enemy of taps and dies so I now only stock high speed steel taps and dies, not the inferior carbon steel or chrome-tungsten steel taps and dies.

[d@rk51d3]

And the higher the grade of ss, the more brittle it is.

[UncleHo]

G'day Stuck :)


I would suggest that you use only grade 5 or 8 high tensile bolts with matching nuts, in Cad plated if available, but you are best off with standard HT, as if used on suspensions, it is usually the following vehicles that have to dodge the wreckage :(




cheers

[Bigbjorn]

G'day Stuck :)


I would suggest that you use only grade 5 or 8 high tensile bolts with matching nuts, in Cad plated if available, but you are best off with standard HT, as if used on suspensions, it is usually the following vehicles that have to dodge the wreckage :(




cheers

Hi Ho. Are you back home from the carpenter's shop? How is the leg? Are they going to put a cad plated Grade 8 bolt in it? Remember to get someone from the right union. Bolts, screws, and plates are fitter's work.

[100inch]

Stainless steel and aluminium show a curve for their ductile strength, instead of a sharp peak figure like normal steel when tested in the lab. Instead, on stainless you are working with the Rm2% rule. marc

[Stuck]

Thanks for the advice. I ended up getting some structural grade bolts. They're graded 8.8 and are galvanised. I'm hoping they'll do the trick.

Cheers,
Anthony.