I look at a breaker and ask myself, "Can I sell this?". If it's not new, the answer is no, and I throw it away. I may have about 10 used breakers between the truck and garage, and have thrown away hundreds.
I now offer to leave screw-in fuses with the customer after being accused of stealing them... when I threw some in my truck on a service upgrade (I give away used fuses).
Dave
