Brake disk condition that would cause heavy pulsing/hammering on braking?

[liquidtiger720]

so, what if there is a noticable "step" in the rotor? Say, the outer .5-1.5 inches of the rotor all the way around is worn down more than the the inner part of the rotor. No shimmy, nothing...just that one little step on the outer circumference of the rotor.