Arai: The Philosophy Behind The Helmets

The shell is measured for thickness at two points in the manufacturing process. Some minor issues with thinness can be remedied with the application of another layer of material to the thin spot. In fact, no matter which factory in which the shell is created, they are all inspected at the main Ōmiya factory – a step that requires the shells to be shipped between factories. The boxes of shells can be seen in the background.