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:
“O, why should Love, like men in drinking-songs,
Spice his fair banquet with the dust of death?”
—Alfred Tennyson (1809–1892)