Yog nqus tau cov kav dej steel siab concentricity

Vim yog lub hydrostatic kis sau du, tab sis kuj xyuas drawing hlab hauv cov qauv kab yeeb axis, axis ntawm mould thiab tej tub ntxhais qws axis raws nraim, sij txhim kho raug qhov khoom, tsis ua tus runout, concentricity thiab straightness siab;