Includes inspection report card Roundness: within 0.5μm (1 to 30), 0.8μm or less (over 30 to 50 or less) Hardness: 653 to 772HV Nominal dimensions (mm): 38 Outer diameter (mm): 71 Thickness (mm): 18 Inner diameter tolerance: ±1.0μm (1至30或更少),±1.5μm(超过30至50或更少),±2.0μm(超过50至100或更少),±5.0μm(超过100至200或更少)