Originally Posted by Mark
As Oldbayrunner suggests, not all stainless steel has the same corrosion resistance or resistance to magnetic attraction. After reading Mark's comment, I went to my basement and dumped out onto my workbench a container holding miscellaneous stainless nuts, bolts, screws, and washers I have bought over the years. I placed a strong magnet over the pile and found that 10%-20% of the hardware was attracted to the magnet. Visually, those items looked identical in appearance to the ones not attracted to the magnet.
In a second test, I went into my kitchen and held a refrigerator magnet against four "stainless" appliances. The magnet stuck to the Kitchenaid refrigerator and dishwasher, but did not stick to the GE stove and microwave.
Mark's magnetic test is a good first step (if the hardware does not stick to a magnet, it is stainless or some other non-ferrous metal). However, some hardware sold as stainless will stick to a magnet. It may still offer reasonable protection from rusting compared to regular steel hardware.
Native Watercraft Manta Ray 11 and Slayer Propel 10
Member - Pro Staff team for Native Watercraft
Author - "Fishing in the Comfort Zone" - light tackle fishing techniques for kayaks and small boats