Material: Meets world industrial standard - SAE J431, Grade 3000 for gray cast iron;
Alloying -- Combining the proper amounts Cu (Copper) and Cr (Chrome) (alloying) achieves the desired tensile strength and hardness. This is combined with stable configuration to enhance GREN rotor anti-heat fade characteristics.
Controlled cooling -- Precise control of temperatures during rotor casting creates a uniform distribution of graphite flakes, thus increasing wear resistance and the ability to dissipate heat. In contrast, premature cooling of cast iron can cause iron brittleness, thus making the brake rotor more likely to warp or crack, especially when heated under hard braking conditions.

Brinell Hardness -- HB215-187 (even hardness within 10)
HB215-187 (even hardness within 10)
Competitor's acceptable range is HB241-170; Ideal hardness is HB210-200 to maximize pad and rotor life. This gives even wear between pads and rotors with maximum braking ability. GREN maintains a controlled hardness much closer to the ideal.
Tensile Strength: 30,000PSI ± 2,000PSI
30,000PSI ± 2,000PSI
High tensile strength minimizes wrapping and cracking. Our specifications are equivalent to domestic manufacturers. This also allows the maximization of the depth of our rotor’s heat dam.

CNC ( Computerized Numerical Controlled ) Machinery --Machine Processing:
Mitsubishi Numerical Control system keeps uniform and accurate tolerances. Our CNC machines allow us to finish both brake surfaces simultaneously. This is then followed by a swirl finish, again simultaneously.
Chuck craft: Only chuck once

Run-out: Perpendicularity of the brake surface to rotating axis (Hub) interface. GREN lateral run-out does not exceed 0.004". This prevents caliper fluctuation and wheel/rotor wobble.
Parallelism (Thickness variation): Both rotor surfaces are machined parallel to each other. GREN parallelism does not exceed 0.0005". This eliminates pedal pulsation.
Heat Dam: A groove cut in the rotor at the hub radius to create a heat barrier. This minimizes the heat being transferred from the rotor to the hub bearings. GREN's deeper designed dam offers maximum protection. This is made possible because of our tensile strength obtained by our casting process.
Surface flatness and finish:The flatness of the rotors' surfaces cannot to exceed 0.0016". GREN uses a non-directional swirl finish to enhance the surface finish which aids in the “Break-in” process.
Balance: All rotors meet GREN's balance specification. An unbalanced rotor will cause vibration and shorten shock, bearing and other suspension parts.
Bolt circle and mounting chamfer:must be concentric to the rotating axis, eliminating imbalance conditions.