Abstract
The formulas, reflecting the characteristic of failure modes, about the ultimate strength of self drilling tapping screw connections fastening two thin steel plates, are presented in this paper. The theoretical investigation on the transfer mechanism of forces makes clear the characteristics of each failure mode. And also, it derives the relations between the ultimate strength and the factors by which it is governed. The value of unknown parameters for establishing the efficient formulas of each failure mode are decided from the data of experiments which examined 124 specimens. Moreover, the availability of these presented formulas is confirmed by the results of another experiments quoted from the reference.
