Hiya everyone
I've had a quick scan down the search results and can't seem to find an answer, nevertheless I apologise if this has already been asked.

I've got a steel screwdriver that's been used for both removing screws and breaking stuff apart like a chisel. I've noticed that the top layer of silver-coloured plating has word off to reveal something like copper underneath. Obviously, not-one makes a screwdriver from copper. Plus it's magnetic.
What is this shiny brown colour? It's doesn't really look like rust - it's not bumpy or patchy, but a single uniform smooth shade right the way along. I've also noticed this effect beneath the top layer of stainless. Could it be what's known as tea-staining?



Just out of interest really but may help with grading

Thanks guys

A