Ball Grade Charts

ABMA
Grade
Round
DIA Toler
Per Ball
Uniformity
DIA Toler
Per Unit
Container
Basic
DIA
Toler
Marking
Increment
Surface
Roughness in
Micro-inches
3 .000003″
(.08)
.000005″
(.13)
±.000030″
(±.75)
.000010
(.25)
0.5
(0.012)
5 .000005″
(.13)
.000010″
(.25)
+.000050/-.000040
(+1.25/-1)
.000010
(.25)
0.8
(0.02)
10 .000010″
(.25)
.000020″
(.5)
+.000050/-.000040
(+1.25/-1)
.000010
(.25)
1.0
(0.025)
16 .000016″
(0.4)
.000032″
(.8)
+.000050/-.000040
(+1.25/-1)
.000010
(.25)
1.0
(0.025)
24 .000024″
(0.6)
.000048″
(1.2)
±.0001″
(±2.5)
.000010
(.25)
2.0
(0.05)
48 .000048″
(1.2)
.000096″
(2.4)
±.0002″
(±5)
.000050
(1.25)
3.0
(0.08)
100 .000100″
(2.5)
.0002″
(5)
±.0005″
(±12.5)
* 5.0
(0.125)
200 .000200″
(5)
.0004″
(10)
±.001″
(±25)
* 8.0
(0.2)
500 .0005″
(13)
.0010″
(25)
±.002″
(±50)
* *
1000 .0010″
(25)
.0020″
(50)
±.005″
(±125)
* *
* Not Applicable (microns)
ITI
Valve Grades
Roundness
DIA Toler
Per Ball
Basic
DIA
Toler
Surface
Roughness in
Micro-inches
48V .000048″ ±.001″ 3.0
100V .0001″ ±.002″ 5.0
200V .0002″ ±.003″ 8.0
500V .0005″ ±.005″ *
* Not Applicable
Balls used in valves usually require close control of roundness and surface finish to insure leak-tight operation. Size variations, however, are not usually critical. The ITI valve ball grades above have been established to complement the ABMA grades for industries using balls for valves and related applications.
ITI
Plastics
Roundness
DIA Toler
Basic
DIA
Toler
500P .0005″ ±.001″
1000P .001″ ±.002″
2000P .002″ ±.003″
3000P .003″ ±.005″
Plastics, because of their reduced hardness and stability, present certain manufacturing problems. The ITI grades above represent the various combinations of tolerances practical to produce.