The part is made by Al-6061. Testing results show that mechanical property data such as  impact-resistance, tensile-resistance, expanding-resistance, anti-wearing properties are much higher than those made by carbon steels. But its weight is less than 1/3 of traditional Pulley. In case of same operation efficiency it can decrease rotating torque and moment of inertia, be designed super-lightly, and reduce availably power consumption caused by affiliated parts near the engine.