A.F.B.M.A. INTERNATIONAL STANDARDS

A.F.B.M.A. STANDARDS (U.S.A.)
AFBMA GRADES
Variation of ball diameter /ROUNDNESS
LOT DIAMETER VARIATION
BASIC DIAMETER TOLERANCE
MAXIMUM INCREMENTS
SURFACE ROUGHNESS
INCHES
µm
INCHES
µm
INCHES
µm
INCHES
µm
INCHES
µm
3
0.000003
0.0762
0.000005
0.127
± 0.00003
0.762
0.000010
0.254
0.0000005
0.0127
5
0.000005
0.127
0.000010
0.254
± 0.00005
1.27
0.000010
0.254
0.0000008
0.02032
10
0.000010
0.254
0.000020
0.508
± 0.00010
2.54
0.000010
0.254
0.000001
0.0254
15
0.000015
0.381
0.000030
0.762
± 0.00010
2.54
0.000010
0.254
0.000001
0.0254
16
0.000016
0.4064
0.000032
0.8128
± 0.00010
2.54
0.000010
0.254
0.000001
0.0254
24
0.000024
0.6096
0.000048
1.2192
± 0.00010
2.54
0.000010
0.254
0.000002
0.0508
25
0.000025
0.635
0.000050
1.27
± 0.00010
2.54
0.000010
0.254
0.000002
0.0508
48
0.000048
1.2192
0.000096
2.4384
± 0.00020
5.08
0.000050
1.27
0.000003
0.0762
50
0.000050
1.27
0.000100
2.54
± 0.00030
7.62
0.000050
1.27
0.000003
0.0762
100
0.000100
2.54
0.000200
5.08
± 0.00050
12.70
0.000100
2.54
0.000005
0.127
200
0.000200
5.08
0.000400
10.20
± 0.00100
25.40
0.000200
5.08
0.000008
0.2032
300
0.000300
7.62
0.000400
15.24
± 0.00100
25.40
0.000300
7.62
-
-
500
0.000500
12.70
0.001000
25.40
± 0.00200
50.80
0.000500
12.70
-
-
1000
0.001000
25.40
0.002000
50.80
± 0.00500
127.0
0.001000
25.40
-
-
2000
0.002000
50.80
0.004000
101.60
± 0.00500
127.0
0.002000
50.80
-
-
3000
0.003000
76.20
0.006000
152.40
± 0.00500
127.0
0.003000
76.20
-
-
Revision n.4