PURPOSE: To enhance soil closing effect in the interior of a steel pipe pile to increase end bearing capacity of the pile by providing a helical protruding strip in the same direction of rotation as that of rotational pressing-in over the outer periphery of the end of the rotational press-in steel pipe pile and forming a helical protruding strip oriented in a reverse direction relative to that of the outer strip.

CONSTITUTION: Outer helical protruding stripe 2 are provided over the outer periphery near the end of a rotational press-in steel pipe pile 1 in the same direction of rotation as that of the rotational pressing-in of the pile, whereas inner helical protruding strips 3 are provided over the inner surface of the pile in a reverse direction with respect to the outer strips 2. The strips 2 function so as to help the pile to be pressed in, while the stripe 5 function so as to consolidate the soil in the pile. As a result, the soil in the end of pile is compacted and hence end bearing force is generated and the excellent property of the steel pipe pile can be further improved.