SUCCESSFUL WELDS – All material combinations listed here have been inertia welded and in all cases a sound metallurgical bond was formed. For some materials, however, the bond does not possess inherent 100% parent metal strength. In other cases, appropriate post-weld treatment may be required to develop full weld-zone strength in materials that have been quenched and tempered, precipitation hardened or work hardened. Stress relieving may be required in hardened materials. It is the responsibility of the customer to evaluate, test and approve all inertia weld applications prior to production.