PURPOSE: To provide sufficient flexibility, recovering strength and ability for keeping stable position after bar bending by providing a core of a alternate layout of flexibility and rigidity, a flexible strip, a flexible or resistive tape and an elastic block.

CONSTITUTION: Strips 4, 4a and 7, 7a of two groups which are oriented in the opposite direction each other provide large flexibility and orientation characteristics to a bar at its end part as well as its intermediate part. In addition, a friction between the strips 4, 4a and 7, 7a and a core 1 generates stability in bar shape. An elastic block 3 laid out alternately with a rigid section 2 in creases resistance and flexibility of the bar. An elastic tape 11 wound around a tape 10 having high rigidity in longitudinal direction increases a pressure of the strips 4, 4a and 7, 7a and also increases the friction between theses elements. At the same time, the elasticity and recovering strength of the bar core 1 are increased, and even when the bar is subject to many bending motions, bar's weight supporting ability is held.