A lot of the stuff that is now available is made off shore... . I was in a store in Spokane that has a large supply of trailer parts and most of them are from off shore... . I than went to purchase from one of my suppliers some OE Dexter stuff and found their prices higher and found the package marked Made in China.....
I finally ended up at my bearing supplier for better prices and quality that I've used for years... yes they are made off shore but have a high enough standard that I'm ok with them... .
I've never replaced springs on my trailers, I have replaced the bushings and bolts, usually they come with plastic bushing and there is a HD brass kit with grease able bolts... If the bolts are installed correctly, they have a swedged end and lock into the hangers and shackles so they don't wear... if for some reason the bolt hasn't been installed correctly and they can turn and rattle than the shackle and hangers can and will wear out... .
Any good axle supplier can usually get you the right kit... . crawl under your trailer and go to the center of the axle, there usually is a tag spot welded to the axle that will give you the brand and model number... .
Most of the axles I've seen are either 1 3/4 or 2" wide with some commercial stuff going as wide as 2 1/2".....
Hope this helps. .