In order to accomplish the project in time, MCC BaoSteel Technology Services Co., Ltd recently has successfully solved the processing problem of Ultra Thin Stay Bolts these days. Differences occurred in the aluminum groove between the new and the old in the aspects of structure and product feature. One of the difference is that the new stay bolts has adjustable tie rods on its two sides. Totally there are over 100 stay bolts, in specification of M42, double-ended studs. The longest length of stay bolt can reach to 4.4 meter while it also requires that the polish rod of the whole parts should be mechanical processing. The project team from MCC’s Heavy-Machinery Branch decided to apply the “Polish Rod Multi-step Cutting Method” processing technology and trial-produced by using the material oddments.

During the trial-production, manipulators used follow-rest to control the cross bending deformation of thin rod and overcame the difficulties of decentration and dislocation. With the help of these measures and the timely adjustment, a reasonable and effective process method took shape by applying new revolving speed, feeding speed and cutting depth. On this basis, the project team accomplished the trial-production and inspection, and later discovered that every parameter of the trial-product met the relative requirements, which symbolized the success of the trial-production.

And it is realized that the biggest slenderness ratio in this project has reached to over 100 times, which should be classified as the hard-produced ultra slender shaft. Based on the classification of technology, when the slenderness ratio of axis parts processed by machinery reaches to over 40 times, then these axis parts should be classified as slender axis. The higher the ratio is, the lower the structure rigidity will be, and the more difficult the process will be.