Ball Grades
ALLOWABLE BALL
DIAMETER VARIATION
is the largest variation in diameter found in any
one ball from the sample lot inspection.
ALLOWABLE DEVIATION
FROM SPHERICAL FORM
is the greatest radial distance in any radial
plane between a sphere circumscribed around the ball surface and any point on
the ball surface.
SURFACE ROUGHNESS
is all those irregularities which
form the surface relief but are not deviations of form or waviness. The
measurement of this characteristic is to be made with equipment meeting the
requirements of and in accordance with Standard ANSI B46.1.
BASIC DIAMETER
TOLERANCE
is the maximum allowable deviation in any ball
mean diameter from the basic diameter ordered.
ALLOWABLE LOT DIAMETER
VARIATION
is the difference between the mean diameter of the
largest ball and that of the smallest ball in the lot.
Grade 
Allowable Ball
Diameter Variation 
Deviation From
Spherical Form 
Surface Roughness
Arithmetical Average 
Basic Diameter
Tolerance 
Allowable Lot
Diameter Variation 
3 
3 µ"
.000003" 
3 µ"
.000003" 
.5 µ"
.0000005" 
30 µ"
±.00003" 
5 µ"
.000005" 
5 
5 µ"
.000005" 
5 µ"
.000005" 
.8 µ"
.0000008" 
50 µ"
±.00005" 
10 µ"
.00001" 
10 
10 µ"
.00001" 
10 µ"
.00001" 
1.0 µ"
.000001" 
100 µ"
±.0001" 
20 µ"
.00002" 
15 
15 µ"
.000015" 
15 µ"
.000015 
1.0 µ"
.000001" 
100 µ"
±.0001" 
30 µ"
.00003" 
16 
16 µ"
.000016" 
16 µ"
.000016" 
1.0 µ"
.000001" 
100 µ"
±.0001" 
32 µ"
.000032" 
24 
24 µ"
.000024" 
24 µ"
.000024" 
2.0 µ"
.000002" 
100 µ"
±.0001" 
48 µ"
.000048" 
25 
25 µ"
.000025" 
25 µ"
.000025" 
2.0 µ"
.000002" 
100 µ"
±.0001" 
50 µ"
.000048" 
48 
48 µ"
.000048" 
48 µ"
.000048" 
3.0 µ"
.000003" 
200 µ"
±.0002" 
96 µ"
.000096" 
50 
50 µ"
.000050" 
50 µ"
.000050" 
3.0 µ"
.000003" 
300 µ"
±.0003" 
100 µ"
.0001" 
100 
100 µ"
.0001" 
100 µ"
.0001" 
5.0 µ"
.000005" 
500 µ"
±.0005" 
200 µ"
.0002" 
200 
200 µ"
.0002" 
200 µ"
.0002" 
8.0 µ"
.000008" 
1000 µ"
±.001" 
400 µ"
.0004" 
300 
300 µ"
.0003" 
300 µ"
.0003" 

1000 µ"
±.001" 
600 µ"
.0006" 
500 
500 µ"
.0002" 
500 µ"
.0002" 

2000 µ"
±.002" 
2000 µ"
±.002" 
1000 
1000 µ"
.001" 
1000 µ"
.001" 

2000 µ"
±.002" 
2000 µ"
±.002" 
2000 
2000 µ"
.002" 
2000 µ"
.002" 

5000 µ"
±.005" 
2000 µ"
±.002" 
3000 
3000 µ"
.003" 
3000 µ"
.003" 

5000 µ"
±.005" 
6000 µ"
±.006" 
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