张力减径在钢管生产中所具有的重要作用是无庸置疑的。我国从六十年代初开始研究这一工艺,1966年第一台工业试验用76mm 张减机诞生。随后,在1966年～1972年陆续制造了两台108mm 张减机和一台177mm 张减机,并引进了一台133mm 张减机。这几台张减机的共同特点是采用液压差动传动。液压差动传动的调速范围大、适应性强, Tension reduction in the production of steel pipe has an important role is beyond doubt. Our country started to study this craft from the early 1960s, and the first industrial experiment in 1966 was born with a 76mm sheet reduction machine. Subsequently, two 108mm machines and one 177mm machine were successively manufactured from 1966 to 1972 and a 133mm machine was introduced. The common feature of these several Zhang Min machine is the use of hydraulic differential transmission. Hydraulic differential transmission speed range, adaptability,