No-rust Magnet

I have some metal that has been exposed to rain, dirt.. everything for over 15 years. It was on the perimeter of a inground pool. It has not rusted at all, so I thought it was aluminum but it attracts a magnet. What kind of metal might this be?
- David Zigon (age 60)
Clifford, PA, USA

Although some stainless steels are almost completely non-magnetic, others are a bit magnetic. Nickel and some of its alloys are magnetic and corrosion-resistant. 

Another possibility is that it might be a magnetic iron alloy with some corrosion-resistant coating, perhaps a nickel alloy.

How can you test what it is? There are, of course, a variety of standard chemical tests, eay to find with an on-line search. Another possibility would be to hammer on it, heat it up etc. If it's stainless, doing things like that might make it more magnetic, since they tend to create little magnetic iron inclusions. If it's nickel, they probably won't make much difference.

Mike W.

(published on 09/19/2013)