In the 1990s, Fengchi created the built-in roll molder for the first time, which completely subverted the traditional steel wheel molding technology, simplified three steps into one of the molding process. And we solved the problem of diameter axial runout of steel wheels (within 0.6mm), and the rims were free from damage, crack, fracture and obvious deformation, and the vacuum tire has no chronic air leakage after the fatigue test and the radial impact test. So, “a device with a set of mould” largely increased the sample development efficiency, and reduces the cost of manufacturing products.