美国钢球、钢珠材质标准

GRADE Ball Dia. variation Deviation from spherical form (U) Surface roughness (U) lot Dia. variation (U) Basic Dia. tolerance (U)
INCH (U)
3 .000003 0.08 0.08 0.012 0.13 ±0.75
5 .000005 0.13 0.13 0.02 0.25 ±1.25
10 .000010 0.25 0.25 0.025 0.5 ±2.5
16 .000016 0.4 0.4 0.025 0.8 ±2.5
24 .000024 0.6 0.6 0.05 1.2 ±2.5
48 .000048 1.2 1.2 0.08 2.4 ±5
100 .0001 2.5 2.5 0.125 5 ±12.5
200 .0002 5 5 0.2 10 ±25
500 .0005 13 13 - 25 ±50
1000 .001 25 25 - 50 ±125
2000★   50 50 - 100 ±125