Braking produces gases, and cross drilling gives the gases a way to escape, thereby increasing contact pressure. In addition, a cross-drilled rotor now has more surface area, and thus cools down more quickly.
Each hole is countersunk for a smooth linear transition at the edge. To reduce the stress and prevent cracking, the holes are also uniquely chamfered to the minimum thickness for exceptional rotor life.
Double disc ground with a taper-free finish ensures parallelism, provides near perfect disc thickness variation, eliminates runout and provides more effective pad and rotor break in.