For this reason, sheets are subjected to a special technological test, the so-called cupping test (according to Erichsen), to characterize their deep-drawing capability. A steel ball with a diameter of 20 mm is pressed into a plate, which is held in position by a blank holder. As the force increases, the ball is pressed in more and more and the sheet metal bulges out – in contrast to the Brinell hardness test – on the opposite side. The maximum depth $$f$$ to which the steel ball is pressed, without cracking the sheet metal, is used to assess the deep-drawing capability. The cupping test can be used to test sheets up to 3 mm thick.