A method of generating compressive residual stresses through a thickness of a metal component comprising the steps: receiving a metal base component (10), which in use is subjected to applied pressure and applying by thermal deposition cladding (16) to one or more surfaces (14) of the base component. The cladding (16) comprises one or more layers of metal or metal alloy. The method also includes, subsequent to the cladding step, applying autofrettage to the clad component thereby generating compressive residual stresses through the one or more layers of metal or metal alloy (16) and at least part way through the base component.