PURPOSE: To increase the bearing force of a pile in a hard ground, by winding up a spiral blade with a specified size by a plurality of rounds and fixing it at the lower end of a steel pipe and attaching an excavating and thrusting blade on it to form a pile member.

CONSTITUTION: The bottom of a steel pipe 1 is closed with a bottom plate 4 and a spiral blade having a diameter as large as about twice of the outer diameter of the steel pipe 1 and a thickness as thick as about 6-2mm is attached by a plurality rounds. And an excavating and thrusting blade 3 is welded by about 1/4 rounds at the under face of spiral blade 2. In this way, even in the case of a hard sand and gravel ground, the excavating blade 3 is penetrated into the ground without idle rotation and hence, a high bearing force can be secured.