You mean the flat male/female connectors as in the picture below? I remove (cut) the plastic covers and cut as much copper I can and then I generally put them (if non-magnetic) in mixed stainless steel. If the ones I got were yellow, they would go in brass. Otherwise, the yards will probably take them as shred (or maybe breakage or stainless turnings, if lucky)

https://cdn.sparkfun.com/assets/9/1/...591d000000.JPG