APR Rotor Material, Casting and Machining

APR Discs are cast from a proprietary high-carbon cast iron alloy that provides excellent durability and stability under the high thermal loads experienced under spirited driving conditions. The slot pattern chosen for our discs provides even heat distribution across the disc surface, while delivering a strong initial bite and excellent release characteristics. In spite of the aggressive slot pattern, we have managed to maintain low levels of noise, vibration and harshness (NVH) under braking. Every single APR disc assembly is measured for run-out and disc thickness variation (DTV) using Swiss measuring equipment. When it comes to QC, there is no batch or statistical quality checking of APR discs. Every single disc is measured. The discs are machined to tolerances are up to three times tighter than the industry norm!

APR Rotor Surface Finish

APR Discs are coated with a proprietary black surface coating. The discs are chemically de-greased before the application of this coating to ensure that no machining fluids or other contaminants that can be absorbed by the brake pads and negatively affect brake performance are left on our discs. The coating is able to withstand extremely high temperatures and is flexible enough to expand and contract without flaking or peeling off the disc surface during the thermal expansion and contraction cycles experienced by brake discs. Our discs require no cleaning or preparation before fitment. Simply ensure that the car's hub is clean and fit the discs as they come out of the box. The black coating will be removed by the brake pads in the pad track areas within the first 4-5 brake applications. The un-swept areas of the disc will remain coated, providing some corrosion resistance.

APR Rotor Maximum Temperature Recording (MTR) System

Our MTR System provides a permanent record of the peak operating temperatures reached by the rotors under actual driving. This information is valuable in terms of checking that you are not overheating the discs. Each tab will change color when the temperature range is met. The final longer red tab will provide a color gradient chart to further refine specific temperatures.

MTR Guide: Blue turns brown at 527 F (275 deg C). Green turns white at 860 F (460 deg C). Orange turns yellow at 1,022 F (550 deg C). Pink turns white at 1,166 F (630 deg C). Lastly the longer red strip turns various shades from 219 F to 2,318 F (104 to 1,270 deg C).