A Cold-drawing Die for Eliminating Steel Pipe Inner Surface Spiral Defect

Elaborated here in the article is a newly-developed cold-drawing die to eliminate the steel pipe inner surface spiral defect. Based on the deformation principle that the metal naturally flows towards where the resistance is minimum,the die can make the inner surface metal of the pipe flows twice circumferentially so as to fix the said spiral defect problem. The steel pipe as processed with the said die has good wall thickness homogeneity,getting the surface quality improved,and thus eliminating the phenomenon of inner bore dimensional inconsistency of the hydraulic cylinder case,and the inner surface spiral defect of the cylinder proper as may occurring during the subsequent processing course.As a result the troubles of vibration and noise as made by the hydraulic cylinder are completely fixed.