Abstract: Elaborated in the article are the main aspects of manufacture of light-wall steel pipes with the Φ140 mm plug mill line by the subjective company, including the manufacturing process, operation, and present equipment conditions.It is emphasized that the critical element which determines the primary yield of the light-wall specific-length pipes is nothing else, but the pipe wall thickness accuracy.Relevant measures are taken, including change of the control methods for shearing speed and piercing velocity, addition of and improvement on the mill built-in roller, and optimization of the rolling mill pass parameters.As a result, the pipe-end wall thickness accuracy is remarkably improved, and thus the wall unevenness-caused metal loss from pipe cutting is reduced, the steel consumption, per ton of pipes is cut down, and the primary yield is enhanced as well.