What screws to use for aluminum

You really should use a coarse thread in a soft metal. I would suggest a 10-24 instead.

yes, you will have problems no matter what the screws are made of, unless they're the same grade as the aluminium. boat masts see this all the time. there is a goop that you can put in around the screws to prevent this problem. note: most boat builders use ss screws for this.

Well, boat masts live in presence of saltwater, whereas that aluminum item will spend its life inside a steel cabinet in a garage.

Try anti-seize. Any auto prats store should have it. It will help to keep dissimilar metals from bonding.

Yep, good point, will do just that.

Somebody makes aluminum nuts/bolts out there. I have the name/number

Also, mebbe nyl>>

Well, if I guess right, you're going to be using these fasteners for bolting conductors together? Providing you keep it air/moisture tight, which most clean boltups are, then you shouldn't have an issue. Corrosion might be an issue under the bolt head, where the joint will be exposed. However, for your very mind environment, I wouldn't even worry about it. Spend your time thinking about more important things.

Nope. These fasteners will be used for attaching case hardware to an aluminum heatsink.

Thanks!

If you want to really do ti up, get some cad plated screws. The cadmium acts as the anode and protects the aluminum. Stainless screws will be worse than low carbon steel in terms of rotting the aluminum. As posted elswhere, some simple anti-sieze should be sufficient for your application.

Are pop rivets out of the question?

Vaughn

It may be overkill, but I usually start out with helicoil thread inserts in aluminum, especially if it's something I'll need to disassemble or periodically tighten.

Pete Keillor

That's a very good idea! Or, epoxy/weld a nut to the other side, if poss.