We are the professional manufacture of linear shaft,and our goods we exported to many countries,we import the machines and technology from Taiwan(a famous area to produce linear series),we produce 50 tons per month.And our goods details as follow:Material: chrome steel. carbon steelLength: to 6000mmDia: 8mm to 50mmHarness: HRC62+/-2Chrome plate: 0.02mmRoughness: Ra0.3Straightness: 0.1/1000We hope we have the chance to cooperate with you!