Different metal interaction

[BrianS]

I have a project planned that will be mostly Aluminum, but I need some really miniature cap screws for it. I know I could machine my own but I don't want to spend all my time making hardware that I could buy. But, I can only seem to find these mini screws in brass. I plan to paint this project, but I was wondering will this create a problem for the finish later on? Like will the different metals interact and corrode or ruin the paint finish later on?

Thanks in advance.
Brian

 

[rleete]

Unless you plan to expose your project to the elements, the amount of galvanic corrosion will be negligible. You need moisture to really cause any action, and by painting you will be sealing it off from the worst of it.

If you are really worried about it, get some stainless screws.

Where are you located? I can post a couple of links for HW here in the States that I use at work. Hewes Fastener and McMaster-Carr are the ones I use most often.

 

[Kermit]

The interaction of different metals to form corrosion is usually associated with salt water or very wet environments. If the bolts will not be touching water, like inside a boiler, I wouldn't worry to much about it. If it is a case of water based corrosion a small piece of zinc will transfer all the eletro-corrosive action to that piece of metal.

 

[Cedge]

Time to share my source for small fasteners in bulk quantity again.

[url]WWW.MICROFASTENERS.COM[/url]

This guy is fast, you can't beat his prices and his products are of good quality. I've placed two separate orders and could not be more satisfied with him. He offers both flavors.... Brass and Stainless. No association... just customer satisfaction.

Steve

 

[joe d]

Time to share my source for small fasteners in bulk quantity again.

[url]WWW.MICROFASTENERS.COM[/url]

This guy is fast, you can't beat his prices and his products are of good quality. I've placed two separate orders and could not be more satisfied with him. He offers both flavors.... Brass and Stainless. No association... just customer satisfaction.

Steve

I'm with Steve on this one, they also stock black alloy, and some nylon fasteners as well. Pretty reasonable prices for number size taps and dies too. Usual disclaimer: No relationship with these guys except being a happy customer. (Also worthy of note, no fuss at all about shipping to Canada, and they usually state the contents of the package to be "hobby supplies" which are generally duty-free)

Joe