I have no reason to believe it is stainless steel. This does not mean that they have no use. I sincerely believe that if you need them for an application that will get them wet from time to time, don't get them a lot of salt on them, or they will be used exclusively indoors then they can be used. They seem pretty decent in the sense that they don't bend by hand. For these reasons, I'm not saying don't buy them, just understand what you're getting. The first thing that made me suspicious that they aren't stainless steel is that they're zinc plated. I've worked with stainless steel enough in my life to know the difference between stainless steel and galvanized metal. If you look closely, as in the joints, you can see a slight accumulation of zinc, which confirms my thoughts. If you don't know what zinc is used for, it's a coating that's applied to standard steel products to protect them from corrosion or rusting. Since stainless steel has these properties right from the start, it does not have to be worn from the start. But there is. Then I checked with a magnet. Not strong for things like picking up tools, but a cheap fridge magnet that has almost no strength. He stayed connected. I've never seen stainless steel that a fridge magnet would stick to. But it easily sticks to ordinary steel. Then I checked for consistency. How well are they aligned, do they all fit properly, etc.? What I found was that there was little consistency with them. Where the joints changed from clip to clip. One of them is a spring clip that you insert. It was misaligned and didn't even line up with the cross-lock where it connected when released back to its normal position. I will return mine because. Well I use them where they get salt, water, ice, snow, mud etc and I know how well galvanized things can stand up to such conditions. Yes, everything will be fine for a few months. Maybe a year. Depending on the conditions. Then let the rust begin. So if you only need them outdoors for a few months. take action. If you just want something cheap. take action. If you want to use something outdoors for the next five years and still look and perform well, I would suggest looking at a different product. I am attaching photos so you can see the weak magnet sticking to them and so you can see the level of quality control and consistency in the manufacture.