AbstractAluminum oxide dispersion strengthened copper (DSCu), used as the heat sink, and AISI 316L(N) type stainless steel (SS), used for cooling pipes, were metallurgically joined to be used as first wall of plasma facing components. Hot isostatic pressing (HIP) was proposed as the joining fabrication technique in the first-wall/blanket components. In this study, fracture toughness and fatigue crack growth rate tests were carried out for the fracture strength evaluation of HIPed joints. Permissible crack lengths during fabrication of first-wall components were evaluated from the results of the fracture toughness tests. In crack growth rate tests, the crack prepared in the DSCu propagated, turned at the HIPed interface, and propagated along it. Therefore, it was found that the crack provided in the DSCu heat sink did not propagate through the SS cooling pipe.