● Material：6063 T5
● Inner Diameter：16~320 mm
● Inner Tolerance：H9~H11
● Inner Roughness：≤ 0.6 μm
● Anodic Oxide Film：≥ 15 μm
● Hardness of Oxide Film：≥ 400 HV
● Straightness：≤ 1/1000 mm