Material: Meets world industrial standard - SAE J431, Grade 3000 for gray cast iron;
Alloying -- add Cu (Copper) and Cr (Chrome) (alloying), to achieve the desired tensile strength and hardness, stable configuration, thus enhancing GREN rotor anti-heat fade characteristics.

Controlled cooling -- Precise control of temperatures during 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)
Competitor's acceptable range is HB241-170;

Ideal hardness is HB200-210 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

Minimize wrap or crack. Equivalent to domestic manufacturers. Allow maximizing the depth of heat dam.

CNC ( Computerized Numerical Controlled ) Machinery -- Machine Processing:
Mitsubishi Numerical Control system keeps uniform and accurate tolerances. Our CNC machines allow us finish both brake surfaces simultaneously, followed by swirl finish simultaneously.

Chuck craft: Only chuck for 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): Two brake surfaces are machined parallel to each other. GREN parallelism does not exceed 0.0005". This eliminates the 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: All rotors' surface flatness are inspected not to exceed 0.0016". GREN uses a non-directional swirl finish to enhance the surface finish to aid in the “Break-in” process.

Balance: All rotors meet GREN's balance specification. 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.