| Grade |
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. |
| Case Depth |
The 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 |
ISO3290/ABMA
