Grade and Tolerance - Inches

Grade

Size Range

Deviation from Spherical Form

Lot Diameter Variation

Allowable Ball Gage Variation

Nominal Ball Diameter Tolerance

Marking Increments

Maximum Surface Roughness 1 in Micro inches "Ra"

3

.006 - 2"

0.000003

0.000003

±0.00003

-

0.00001

0.5

5

.006 - 6"

0.000005

0.000005

±0.00005

-

0.00001

0.8

10

.006 - 10"

0.00001

0.000010

±0.00005

-

0.00001

1.0

25

.006 - 10"

0.000025

0.000025

±0.00010

-

0.00001

2.0

50

.006 - 10"

0.00005

0.000050

-

±0.0002

0.00005

3.0

100

.006 - 10"

0.0001

0.0001

-

±0.0005

-

5.0

200

.006 - 10"

0.0002

0.0002

-

±0.001

-

8.0

1000

.006 - 10"

0.001

0.001

-

±0.005

-

-

Grade and Tolerance - Metric (Millimeter)

ABMA Grade

Deviation from Spherical Form

Lot Diameter Variation

Allowable Ball Gage Variation

Nominal Ball Diameter Tolerance

Marking Increments

Maximum Surface Roughness1 in Micro inches "Ra"

3

0.0008

0.00008

±0.0008

-

0.00025

0.012

5

0.00013

0.00013

±0.0013

-

0.00025

0.02

10

0.00025

0.00025

±0.0013

-

0.00025

0.025

25

0.0006

0.0006

±0.0025

-

0.00025

0.051

50

0.0012

0.0012

-

±0.0051

0.00127

0.076

100

0.0025

0.0025

-

±0.0381

-

0.127

200

0.005

0.005

-

±0.025

-

0.203

1000

0.025

0.025

-

±0.127

-

-