Abstract: Based on the theory of screw tension test, the quantization of screw connection was researched aiming in the aerospace-used cast magnesium alloy. And the basic properties of foundation feature were systematically given by testing the screw torsion strength, torsion-tension relation, axial bearing capacity and reuse performance, which had guiding significance for engineering application.

Key words: Magnesium alloy, Screw thread, Load-carrying property