We manufacture our product to meet all major standards (ISO 3290, DIN 5401, JIS B1501).
Our trained engineers also work closely with our customers to develop products most suitable for
their applications.
Technical Definitions
GradeA specific combination of dimensional form and surface roughness tolerance
Nomintal ball DiameterThe diameter value that is used for the purpose of general identification of a ball size. Measured by two parallel plane tangent to the surface of the ball.
Mean Diameter of a BallThe arithmetical mean of the largest and the smallest single diameter of the ball.
Lot Mean DiameterThe arithmetical mean of the mean diameter of the largest ball and that of the smallest balls in the lot. Lot is the definite quantity of ball manufactured under uniformed condition.
Lot Diameter VariationThe difference between the mean diameter of the largest ball and that of the smallest ball in the lot.
Diameter ToleranceThe maximum allowable deviation of any ball mean diameter from the nominal ball diameter.
SphericityThe greatest radial distance in any radial plane between a sphere circumscribed around the ball surface and any point on the ball surface.
Surface RoughnessSurface roughness consists of all those irregularities such as crack,cuts and dent,which surface relief. And it is conventionally defined within the area where deviation of form are eliminated.
HardnessThe measure of resistance to penetration of the ball surface or truncated flat of the ball by a specific indenting shape.
Case DepthThe distance measured radially from the surface of the ball to the point where the ball hardness becomes Rc 50. This term is applicable to case hardened ball only.
Grade and Tolerance
GradeVDSWVDLRa
30.080.080.160.010
50.130.130.250.014
100.250.250.500.020
200.50.51.00.032
401.01.02.00.06
601.51.53.00.08
802.02.04.00.1
1002.52.55.00.1
2005.05.0100.15
3007.5 7.515x
50012.512.525x
800202040x
1000252550x
20005050100x
Unit : micronmeter(μm)VDL : Lot diameter variationVDS : Ball diameter variation
Ra : Unit of surface roughness(μm)W : Deviation from spherical form(Roundness)Refernce : ISO 3290-2008
