Abstract: An undetachable flange joint characterized in that it essentially comprises a pair of semicircular clamp halves of which cross-sectional configuration is designed to tightly fit the outer configuration of a pair of tapered flanges to be joined, said clamp halves having curled portions at their both ends, and two annular links adapted to be engaged around the respective curled end portions so that the pair of flanges are tightly joined to one another by firmly holding the whole flanges by means of the clamp halves under wedging force.

Abstract: A method of making a clamp used for a supercharger in an internal combustion engine is initiated by cutting out an unworked clamp half from a plate material. The half is then formed such that it is semicircular in front elevation and the opposite ends extend outwardly. Other clamp half is made in the same manner. An unworked link is cut out from a plate material and then its plane strain is corrected. Further, the link is chamfered and hardened. The halves are arranged in circle and the worked link is inserted into one ends of the halves. Finally, these ends are curled around the link.