Grub/Set Screws as pole pieces - which is the most magnetic?

[peskywinnets]

I need to order some grub screws for my Sustainer coils ....they're available in two finishes that suits my needs....

Zinc coated steel
Stainless steel.

Now I'm pretty sure I have some zinc coated steel screws in my screw drawer that aren't magnetic in the slightest (there again I could be wrong - they might not be steel inside, but they are bright/shiny!), so can aynone say that if steel is given a zinc coating that it loses some/all magnetism?

Of the two types above, which would be the most magnetic?

[jonson]

If your screws Pesky have no magnetic properties at all then they are stainless. Not all stainless is nonmagnetic but most commercial stainless screws are. Never found zinc plate to stop any properties at all as I use a lot in another field and a dropped box of them is quickly picked up with a big magnet.

[David Schwab]

The zinc plated steel is the one to use.

[David King]

Zinc is fine unless you want to anneal them indoors over a torch. The zinc fumes are very toxic so do that out of doors.

[Possum]

....

You can remove zinc plating quickly with muriatic acid, I do this all the time....

[peskywinnets]

You can remove zinc plating quickly with muriatic acid, I do this all the time....

Thanks to you all for replying.

I've no issues with the zinc plating *unless* it impedes the underlying magnetic qualities of the grub screw.

[jonson]

Here in the uk and probably everywhere else they should be available chemically blacked as well. I know unbrako's range is huge. We call, as you may know Muriatic acid/ Hydrochloric over here in the uk and that you can get a small quantity from your local plater. You can also do your own blacking by heating them in a wire basket till they are cherry red and dunking them straight away in some real black dirty sump oil. That has no effect magnetically whatsoever.

[David Schwab]

Here in the uk and probably everywhere else they should be available chemically blacked as well.

I have a box of the black set screws I'm using on a project. It's the same type of screw that DiMarzio uses.