With no screws, the spin-hairline is continuously applied to aluminum. A concentric circle spin pattern is applied breaking away from the usual aluminum hairline. We maximized the high quality of the aluminum by anodizing after the C-cut process. We also improved the pitch value (0.15 pitch) for high quality hairspin. FM37 is as slim as 10.2 mm using 0.6 mm thick aluminum. The finishing was enhanced by applying the same step height to the middle, the front and the back aluminum. Anodizing colors (titan/black) were developed so that they were suitable for mass production and yield. The spin-hairline on the front prevents fingerprints and enhances durability.