Patent ID: 6718813
Filing Date: 2004-04-13
Classification: B21D,B21K,Y10T

Abstract:
A pipe rack forming method of forming a rack tooth having a final tooth profile of a fixed tooth bottom height and tooth top height, in a part of a pipe material comprising:preparing a tooth profile metal mold having a plurality of tooth profile portions each having a different height position of tooth bottom forming surfaces; holding a raw pipe material by a holding portion of a holding metal mold, sequentially pressing the tooth profile portions in which the tooth bottom height applied to a part of the raw pipe material is reduced in sequence repeatedly pressing and a moving forward and backward a mandrel, the mandrel having the same size every time, to an inner periphery of the raw pipe material when the tooth profile portions in the tooth profile metal mold press a part of the raw pipe material, and forming a rack tooth having a final tooth profile.