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摘要

The two objects to be joined have their smooth sides facing each other, and the primary pins used, which are two or more in number than those secondary, are driven into one of the objects from its flat side and at right angles to it a depth so that their part is wholly within the material and below the surface of the smooth side. The second object, with a movement direction parallel to the line of the secondary pins towards the first object, is then moved against the first object with the secondary pins penetrating the smooth side of the second object.