Originally Posted by gearbasher

My guess: After the Allen hit, it slid along the face of the stay and put a light scratch in the top coat.

Originally Posted by vane171

That's also what I thought of that light scratch. Also could have been there due to another prior handling.

The OP could also take a close up picture with camera at macro setting and with as high resolution he can get, under different lighting from a lamp, a flashlight or with camera flash and under different angles (camera flash at close distance doesn't always work well). Close up pics take few tries to come out good but if you manage, they show what you can't quite see with your eyes. On the other hand, such macro pics can scare you, things that looked so nice when looked at with your eyes all of sudden reveal themselves full of dust and scratches.

Originally Posted by Camilo

I agree. With the small amount of force caused by a light weight crank, spinning at a relatively slow speed for a short distance, and a light weight tool involved (I'm no engineer or physicist, but that's how I would analyze the impact).... how can the OP possibly tolerate the rocks thrown up by his tires and/or accompanying cyclists or passing cars. Or less than gentle leaning against the wall or car, or.... Dings happen. this is a ding.