To provide an improved structure of a vehicle body frame assembly having reduced weight and can easily be secured.

The vehicle body frame assembly 10 comprises a pair of longitudinally extending side rails 11 and 12 having a plurality of transverse cross members 13, 14 and 15 extending therebetween. The cross member is a multiple piece structure, and the central portion is formed from a first metallic material, while the end portions are formed from a second metallic material. The end portions of the cross member can be secured to the ends of the central portion by any desired process, such as by magnetic pulse welding. The cross members 13, 14 and 15 can be secured to the side rails 11 and 12 either by magnetic pulse welding or by regular welding.