A specific combination of dimensional form and surface roughness tolerance.
Nomintal ball Diameter
The 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 Ball
The arithmetical mean of the largest and the smallest single diameter of the ball.
Lot Mean Diameter
The 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 Variation
The difference between the mean diameter of the largest ball and that of the smallest ball in the lot.
Diameter Tolerance
The maximum allowable deviation of any ball mean diameter from the nominal ball diameter.
Sphericity
The greatest radial distance in any radial plane between a sphere circumscribed around the ball surface and any point on the ball surface.
Surface Rounghness
Surface 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.
Hardness
The measure of resistance to penetration of the ball surface or truncated flat of the ball by a specific indenting shape.