Machine tool material column column material common to HT250, this material strength, wear resistance, heat resistance are good, good damping properties, casting performance is excellent, the need for artificial aging. In addition to frequently used there HT200 HT300 or ductile iron, depending on the job requirements. Machine tools Column Column processing requirements and processing requirements mainly in its guide surface accuracy and hardness test with the machine bed rail surface rather, is generally not more than three, depending on the hardness of the material guide, quenching HT250 were completed --- -HRC46-50 HT300 ---- HRC48-52, quenching depth 2.5-3mm. Role machining center column machines column mainly on the headstock play a supporting role in meeting the Z axis motion. Now widely used is the double column frame design form, for medium and large mobile upright fixed to a carriage. Because the column is an important component of the bed and connected to the spindle, magazine, so it must be designed to get attention. For the spindle is concerned, the correct installation column machining center for qualified parts has not ignored, and post installation mainly reflected in the verticality with the workbench. Hebei's first industry Tools Co., a large number of production and sales of cylindrical tolerance causes: 1) the workpiece rotation axis direction of the pump power imbalance and cast iron table 2) headstock and tailstock does not coincide with the axis 3) Process System axis to the elastic deformation is not the same 4) rigid bad piece of elastic deformation too 5) Ground major axis, thimble top tight bend leaving the workpiece 6) center frame improperly adjusted 7) cast iron table rail lubrication pressure is too great in the movement to generate swing 8) leaving the grinding amount is too large workpiece bending 9) Coolant insufficient measures to prevent a) re-centering cast iron table or machine table 2) at the tailstock floor mat or pad of paper thin copper wait