GradeAvailable Size RangeBall Diameter Variation
(µ m)
Deviation from
Spherical Form (µ m)
Lot Diameter Variation (µ m)
101/16" ~ 1"0.250.250.50
281/16" ~ 1"0.70.71.40
401/16" ~ 1"112.00
601/16" ~ 1"1.51.53.00
1001/16" ~ 1"3.03.06.00
2001/16" ~ 1"5.005.0010.00
3001/16" ~ 1"7.627.6215.20
5001/16" ~ 1"12.7012.7025.40
10001/16" ~ 1"25.4025.4050.80

 

GradeAvailable Size RangeGauge Interval
(µ m)
Preferred Gauge (µ m)
101/16" ~ 1"1-10, ....., -1, 0, +1, ....., +9
281/16" ~ 1"2.00-12, ....., -2, 0, +2, ....., +12
401/16" ~ 1"4.00-16, ....., -4, 0, +4, ....., +16
601/16" ~ 1"5.00-25, ....., -5, 0, +5, ....., +25
1001/16" ~ 1"10.00-40, ....., -10, 0, +10, ....., +40
2001/16" ~ 1"15.00-60, ....., -15, 0, +15, ....., +60
3001/16" ~ 1"--
5001/16" ~ 1"--
10001/16" ~ 1"--


Definition :

  • Ball Grade : A specific combination of dimensional form, surface roughness and gauge. A ball grade is designated by a grade number.

  • Ball Diameter Varitation : The difference between the largest and the smallest actual single diameters of one ball.

  • Deviation from Spherical Form : The greatest radial distance in any radial plane between a sphere circumscribed around the ball surface and point on the ball surface.

  • Lot Diameter Varitatiion : The diffecrence between the mean diameter of the largest ball and that of the smallest ball in the lot.

  • Surface Roughness : All those irregularities of the surface which are conventionally defined within a section of the area where deviations of form and waviness are eliminated. Ra = Arithmetical mean deviation.

  • Ball Gauge : The amount by which a lot mean diameter should differ from the nominal ball diameter, this amount being on of an established series of amounts.