Magnesium alloy tube have the advantage over aluminum alloy. 1) Specific Gravity is smaller. So using Mg alloy as the EV frame can save electrical energy and prolong the storage battery life. 2) Specific strength is higher. So the small thickness can achieve the demands. 3) Elastic Modulus is big. So the ability of absorbing impact and sound is good 4) The ability resisting corrosion of organic compound and alkali. 5) Magnesium alloy is environmental, it is can 100% recycle.