空心活塞杆  供应各种规格附注(Remark)外径精度(External Diameter Accuracy)F8表面粗度(Surface Roughness)Ra0.2μm～Ra0.4μm硬铬厚度(Hard Chrome Thickness)25Micron±5My表面硬度(Surface Hardness)HV 800 (Minimum) up标准长度(Stardard Size)1M～6M标准尺寸(Standard Size)30φ～100φ材质(Material)JIS STKM13C OR STKM11A