Topic: Aluminum Nuts

[srbakker]

I'm wondering what you gurus out there think of the safety of using aluminum hardware.

There are obviously non stressed places where this is fine - mounting electronics etc - but I see a lot of more suspect uses, like sprocket nuts, brake caliper bolts (not mounting bolts, but still) and one guy who was using aluminum nuts and bolts to hold his rotor on!

I have access to a lot of cheap aluminum, but some of those uses kind of freak me out - I'm just not sure it would be strong enough.  Then I see CycleX selling aluminum sprocket nuts on EBay.

Am I just too worried about this?

[Stev-o]

I'm a firm believer in using stainless hardware, it really is not expensive when bought at a specialty store.
Aluminum is a soft metal but could be used on non critical areas.

[FunJimmy]

I'm a firm believer in using stainless hardware, it really is not expensive when bought at a specialty store.
Aluminum is a soft metal but could be used on non critical areas.

It is a common misconception that stainless steel is stronger than regular steel. In fact, due to the low carbon content, stainless steel cannot be hardened. Therefore when compared with regular steel it is slightly stronger than an un-hardened (grade 2) steel fastener but significantly weaker than hardened steel fasteners.

Aluminum would be ok for non stressed fasteners, but really, how much weight can be saved there.
As for sprocket nuts, maybe. There isn't a lot of stress on the nuts, but again.....is it worth it?

FJ

[BobbyR]

My company makes Subway and Commuter rail cars. The bodies are stainless and a lot of non critical brackets. Critical assemblies like the wheel trucks are all welded malleable mild steel assemblies to resist cracking. The   the crash crumple zones are all steel as are the collision posts to protect the train operators. Stainless is not as predictable as steel.

If you use Aluminum nuts and bolts you most certainly use an anti seize.