To easily insert a screw into a hollow bore by a method wherein rolling rollers, each slightly projecting beyond the outer diameter of the screw, are provided at a spiral blade at the end of the screw, and the rolling rollers are brought into contact with the interior of the hollow bore.

A screw 10 is equipped at its center shaft 11 with a spiral blade 12 and is enabled to be inserted into a hollow bore of a pile 13. The outer diameter of the spiral blade 12 is smaller than the inner diameter of the hollow bore of the pile 13. The spiral blades 12 in plural numbers are used, being connected together, depending on the length of the pile 13. A plurality of rolling rollers 14, each projecting slightly beyond the outer diameter of the screw 10, are provided at the spiral blade 12 positioned at one end of the screw 10. On inserting the screw 10 into the hollow bore of the pile 13, the rolling rollers 14 are brought into contact with the interior of the hollow bore of the pile 13 and thereby friction resistance between the internal wall of the hollow bore of the pile 13 and the screw 10 can be reduced sharply, enabling smooth insertion to be possible.