Abstract: A linear friction welding process provides two members to be joined together into a final product, where each of the members has a major outer surface, where one of the two members is a stub which is surrounded, at least in part, on its outer major surface by a collar. The stub is generally restrained without substantial restraining contact on its outer major surface by tooling, thereby eliminating the risk that tooling will cause physical or chemical damage to the final shape. Thereafter, pressure and relative movement are applied between said members to linear friction weld the members together. A collar comprises a major inner surface surrounding a portion of a major outer (lateral) surface of a member to be linear friction welded, and further comprises a radially outer surface which extends a surface to be interfaced of the member. The collar has an outer lateral surface which may be curved in order to prevent stress and cracking of the collar during linear friction welding.