The beginning of December 2009, Technology Center redesigned the rolling tools for uniformity of wall thickness and lighting internal spiral, and adopt piercing-reducing abbreviated system, all these resulted our success to produce 4 joints 351 X 50mm 27SiMn hydraulic prop pipe. dimensional accuracy and surface quality are in comply with relevant technical requirements, these pipes will be delivered to the end user for trial. Because of the abbreviated system not include rolling process compare with normal system, it makes a lower production cost, enhanced product competitiveness.

 

         Also the news, after getting the succeed of 339.72×12.19mm big OD surface casing, Technology Center optimized the tool design and process improvement, recently 219 rolling division succeed on performing mass production of 339.72×9.65mm big OD thin wall casing. During the rolling load 3217 joints billets, 2964 joints are qualified, Synthetically qualification rate is 92.14%. This succeed pioneered hits the most in domestic with similar machine set.