If they are made of steel or iron, then most large cities have locations where you can drop them off for recycling.
In Dallas, there are several drop off locations operated by the city. I throw everything steel into a box in the garage and when it gets full, I take it to the drop off center on Saturday after breakfast and throw it in the bin. I take old chainsaw chains, bolts, DISH satellite dish, old T-posts, old edger blades, old padlocks, old lawn chairs, broken hammer, old metal trash can, old broken bicycle, pieces of rebar, chicken wire, old firewood rack, etc. Anything that is steel/iron. I have a magnet in a kitchen drawer and use it to test an object if there is any question.
They then take all of this stuff from the drop off to a foundry where they melt it down and make new steel I-beams, plate metal, Aircraft Carriers, Ticonderoga class Cruisers, etc.
I lived in Colorado several years ago, and there was a drop off location just outside the city limits. It was actually at the foundry, and you could see smoke and flashes of light coming from inside where they were melting the metal.
I figure it's better to recycle it than just throw it all in the landfill.
One caveat though, do not put the rotors in with the aluminum or steel cans, it will ruin the machine that shreds the cans. There is a separate place where scrap steel/iron should be dropped off. Usually you can contact City Hall in your location and they will tell you where to go.