Double column cnc vtl, has two ramstoolposts on the crossbeam. ■ cnc controlled with siemensfanuc, automatic speed changing with stepless in each range. Encoder is in chuck for thread cutting and constant line speed cutting. ■ all the guideway are grinded and handled by supersonic frequency induction hardening (hrc≥50), excellent casting(ht250gg25) with artificial heat ageing. ■ best copoments: thk-japan ballscrew, nskina bearing, compass hydaulic parts, german-mecano control panel, siemensschneiderabb electric units.