Because it is stainless steel, I think that it is hard to rust to some extent. It was good to use it because there are only a few spring washers entering and there is much detachment and easy to eliminate the spring washer.
I did not need the SW, but I did not have the item as I wanted, I bought this item without a help. I thought that it would be better to remove the SW, but it did not come off. That was the reason for decreasing by one star, and otherwise it was a good product as expected. I also need a lineup without SW.