Tubular body used for power transmission shaft and power transmission shaft

A tubular body used in a power transmission shaft that transmits power by rotating and that is made of a fiber reinforced plastic, comprising:

• a tubular main body portion that is centered at an axis;
• a connection portion which is continuous with an end portion of the main body portion and to which a coupling member is joined;
• and
• an inclined portion that is formed between the main body portion and the connection portion and that decreases in diameter while extending from the main body portion toward the connection portion, wherein
• a linear rupture portion that fails when load inputted in an axial direction exceeds a predetermined value is formed only on an outer peripheral surface of an end portion of the main body portion on the inclined portion side,
• the rupture portion is a cut line or a groove extending in the axial direction of the main body portion, and
• the cut line or the groove does not penetrate through the main body in a thickness direction of the main body.