... ,top rail,slider block,working table,lower cylinder,upright column,locknut and adjusting nut.The precision is adjusted by adjusting ... top or drawing process.5.Upright Column and lockoutThe material of upright column is 45# forged steel,and has process in drawing temper ... produced in blue handle,the connection between the upright colume and locknut is screw thread connection.6.Stroke limit device ...