MANUFACTURING METHOD OF RECTANGULAR BEAM USING PIPE

摘要

Disclosed is a method for manufacturing a mold for a square pipes having rounded edges using a pipe having a ring-shaped cross section. By pressurizing a material pipe having a round cross section with a mold having a molding groove, a mold for a square pipe having rounded edges can be formed. The perimeter of the inner circumference of the molding groove corresponds with the perimeter of the outer circumference of the material pipe.