What blasting media should be used to remove rust and clean nuts and bolts?

 

I have always used sand or nickle slag. Its the cheapest and not going to hurt heavy steel like nuts or bolts.

 

http://www.evapo-rust.com/

Leave it in there about a day. Solution goes from green color to dirty rusty color. Spray the screws clean with brake clean and they are like new. Of course anything heavily pitted wont look so good but if you just have surface rust it will remove the rust without touching the black (or plated finish).

Buy it at Harbour Freight.

I used to blast and tumble until i found this stuff.

No joke this stuff works.