Steel has different properties dependant on how it is heated then cooled. Sugihara bars may go through the process of heating and cooling up to 4 times on different parts of the bar in order to gain maximum performance. The rails need to be accurately cut and hardened but over hardening can make them brittle. The bar body needs to be stiff yet flexible. We have used a number of different chainsaw bars over the years including all the major manufactures. Sugihara bars are the hardest wearing bars out there. Even their laminated bars will outlast rivals.