Patent ID: 7954692

Claim:
A method of joining members, comprising: forming a first hole that extends through a first surface and second surface on a first portion of a main member; forming a second hole that extends through a third surface and a fourth surface on a second portion of the main member, the second hole and second portion being opposite to said first hole and first portion; inserting an auxiliary member, including a tip end and a base end, into the first and second holes such that the tip and base ends are disposed in the second and first holes of the second and first portions of the main member, respectively; rotating and pushing a joining tool against the tip end of the auxiliary member to clamp the second portion of the main member in a direction of thickness thereof via softening of material of the auxiliary member due to frictional heat and plastic flow; releasing the joining tool from the auxiliary member to allow the material of the auxiliary member to solidify; rotating and pushing the joining tool against the base end of the auxiliary member to clamp the first portion of the main member in the direction of thickness thereof via softening of the material of the auxiliary member due to frictional heat and plastic flow; and releasing the joining tool from the auxiliary member to allow the material of the auxiliary member to solidify, wherein, the steps of rotating and pushing the joining tool against the tip and base ends radially deform the tip and base ends toward the second and first portions of the main member, respectively, such that a material of the auxiliary member at the tip end clamps against the third and fourth surfaces of the second portion by clamping the third and fourth surfaces within the tip end, and a material of the auxiliary member at the base end clamps against the first and second surfaces of the first portion by clamping the first and second surfaces within the base end.