Abstract: It is very critical for manufacturing the anti-collapse casing to minimize the residual stress of the pipe body.Such residual stress of the pipe body can be considerably reduced by both employment of the hot-straightening process and improvement of the dimensional accuracy of the pipe itself.The Assel mill can not only ensure higher dimensional accuracy of the pipe, but also enhance the anti-collapse performance of the pipe due to its ﹛111﹜ texture as resulting from the cross-rolling process.