gear shaft 1.Lenths:20mm~800mm, Straightness:0.01mm 2.Diameter:2mm-50mm, Roundness: 0.005mm. 3.Material, steel, ss steel et Gear Shaftproduct ... name:gear shaft Hardness:from 58 degree to 62 degree Harden part ... :we can offer some special requirments such as threading,reducing shaft diameter,coaxial holes drilled and tapped