Stainless bolts or screws used in aluminum structures

[dcceecy]

Can we use Stainless bolts or screws in aluminum structures?

will that cause corrosion due to two different metal in direct contact?

thanks.

 

[connectegr]

We do it all the time.

http://www.FerrellEngineering.com

 

[MikeHalloran]

IF the joints stay dry, corrosion is not a problem.


Mike Halloran
Pembroke Pines, FL, USA

 

[drawoh]

dcceecy,

Most of the things I work on are aluminium with stainless steel screws. I am not aware of corrosion problems.

All of your aluminium should be anodized, chemical filmed or painted.

JHG

 

[Ron]

Same here...do it all the time. Not an issue.

 

[csd72]

I tend to use galvanised screws in that application as it is very close in corrosivity to aluminium.

 

[hokie66]

There is a nice foot/bike bridge near me, 52 metre span aluminum trusses, all stainless steel bolts in connections. Not a weld anywhere.

 

[Ron]

csd72...that works fine as long as the galvanizing is intact...if there is a breach, corrosion can be rapid.

 

[graybeach]

When you have a lot of the anode (aluminum) and a little bit of the cathode (stainless steel), there will not be a problem with corrosion.

 

[csd72]

graybeach,

Interesting point, but I always wondered if there would be localised corrosion of the aluminum around the hole.

 

[IFRs]

GrayBeach has it right - although AL and SS are further apart than most compatible materials the huge ratio of area of AL to SS keeps corrosion at bay. SS fasteners are used in mill finish AL structures in industrial applications all the time with no issues over decades of exposure.