Twisted cable

A twisted cable, comprising:

• a central wire and plural surround wires, the surround wires arranging around the central wire, the surround wires being arranged in layers which are concentrically defined outwardly from the central wire as an inner layer, a middle layer, and an outer layer;
• wherein the surround wires are classified according to sizes of areas of transversal cross sections thereof, and classified into first wires, second wires, third wires, and fourth wires, which are ranged from the smallest to the largest;
• wherein each transversal cross section of each surround wire is perpendicular to an axial direction of the surround wire;
• wherein the inner layer comprises at least six second wires, size of area of transversal cross section of each second wire is not larger than size of area of transversal cross section of the central wire;
• wherein the middle layer comprises plural first wires and plural third wires, the third wires are interspersed between any two adjacent first wires of the first wires, quantity of the first wires of the middle layer, quantity of the third wires of the middle layer, and quantity of the second wires of the inner layer are the same;
• wherein the outer layer comprises plural fourth wires, quantity of the fourth wires of the outer layer is equal to total quantity of the first wires and the third wires of the middle layer;
• wherein each of the fourth wires has an inner surface facing the central wire and an outer surface away from the central wire, curvature of the outer surface is smaller than curvature of the inner surface from a cross sectional viewpoint;
• wherein the surround wires are twisted on the central wire together.