PURPOSE: To secure bending strength and rigidity without damaging the joining area by bonding different kinds of plastic reinforced fiber layers as an integrated entirety in each stage of stepped metal fittings L-shaped in section.

CONSTITUTION: In each step of stepped metal fittings L-shaped in section, layers of plastic reinforced fibers are sequentially bonded and integrated as an entirety into a fiber-reinforced plastic lamination and connection member 1. Fiber- reinforced plastic layers 3, 4 are bonded together by way of an adhesive using the fiber-reinforced plastic lamination and connection member 1. Accordingly, bending strength and rigidity can be secured with an ensured transmission of pulling force and without fear for damaging the joining area because no filling member is used.