(100) 1/4" (6.35mm) G100 Precision Chrome Steel Bearing Balls New Old Stock 

Bearing Grade Steel 
Chrome Steel Ball 

Higher precision than G25 Chrome Balls 

A.F.B.M.A. Ball Grades

GradeAllowable Ball Diameter VariationDeviation From Spherical FormSurface Roughness Arithmetical AverageBasic Diameter ToleranceAllowable Lot Diameter Variation
33 µ"
.000003"		3 µ"
.000003"		.5 µ"
.0000005"		30 µ"
+/-.00003"		5 µ"
.000005"
55 µ"
.000005"		5 µ"
.000005"		.8 µ"
.0000008"		50 µ"
+/-.00005"		10 µ"
.00001"
1010 µ"
.00001"		10 µ"
.00001"		1.0 µ"
.000001"		100 µ"
+/-.0001"		20 µ"
.00002"
1515 µ"
.000015"		15 µ"
.000015"		1.0 µ"
.000001"		100 µ"
+/-.0001"		30 µ"
.00003"
1616 µ"
.000016"		16µ"
.000016"		1.0 µ"
.000001"		100 µ"
+/-.0001"		32 µ"
.000032"
2424 µ"
.000024"		24 µ"
.000024"		2.0 µ"
.000002"		100 µ"
+/-.0001"		48 µ"
.000048"
2525 µ"
.000025"		25 µ"
.000025"		2.0 µ"
.000002"		100 µ"
+/-.0001"		50 µ"
.000048"
4848 µ"
.000048"		48 µ"
.000048"		3.0 µ"
.000003"		200 µ"
+/-.0002"		96 µ"
.000096"
5050 µ"
.000050"		50 µ"
.000050"		3.0 µ"
.000003"		300 µ"
+/-.0003"		100 µ"
.0001"
100100 µ"
.0001"		100 µ"
.0001"		5.0 µ"
.000005"		500 µ"
+/-.0005"		200 µ"
.0002"
200200 µ"
.0002"		200 µ"
.0002"		8.0 µ"
.000008"		1000 µ"
+/-.001"		400 µ"
.0004"
300300 µ"
.0003"		300 µ"
.0003"		 1000 µ"
+/-.001"		600 µ"
.0006"
500500 µ"
.0002"		500 µ"
.0002"		2000 µ"
+/-.002"		2000 µ"
+/-.002"
10001000 µ"
.001"		1000 µ"
.001"		 2000 µ"
+/-.002"		2000 µ"
+/-.002"
20002000 µ"
.002"		2000 µ"
.002"		5000 µ"
+/-.005"		2000 µ"
+/-.002"
30003000 µ"
.003"		3000 µ"
.003"		 5000 µ"
+/-.005"		6000 µ"
+/-.006"
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
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.