| 摘要 |
PROBLEM TO BE SOLVED: To provide a spiral blade at one end of a metal pipe for producing a foundation pile easier and further improving the driving performance. SOLUTION: A thicker meat portion of a metal pipe 1 where the thickness of meat is made larger at one end side 1a and the pipe end surface 2 is made to a spiral surface, from a spiral pipe end face 2 to a radial direction, the thick blade at the root portion 3a is extended and formed in one body by casting, and excavating blades 4...4 extruded in the axial direction are protruded as one body in the configuration.
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