Brake Dust
When braking force is applied, the act of abrasive friction between the brake pad and the rotor wears both the rotor and pad away. The "brake dust" that is seen deposited on wheels, calipers and other braking system components consists mostly of rotor material. Brake dust can damage the finish of most wheels if not washed off. Generally brake pad that aggressively abrades more rotor material away, such as metallic pads, will create more brake dust.
Read more about this topic: Disc Brake
Famous quotes containing the word dust:
“Or ever the silver cord be loosed, or the golden bowl be broken, or
the pitcher be broken at the fountain, or the wheel broken at the
cistern.
Then shall the dust return to the earth as it was: and the spirit
shall return unto God who gave it.
Vanity of vanities, saith the preacher, all is vanity.”
—Bible: Hebrew Ecclesiastes (l. XII, 6–7)