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INTRODUCTION
The tolerancing on the drawing should be complete to ensure that the elements of size and geometry of all features are controlled, i.e. nothing shall be implied or left to judgement in the workshop or in the inspection department.
The use of general tolerances for size and geometry simplifies the task of ensuring that this prerequisite is met.
GreatWell Metals performs the international tolerance standard ISO2768 for its metal precision casting products.
GERENRAL CASTING TOLERANCES
Table 1 - Permissible Deviations for Linear Dimensions Except for Broken Edges
| Tolerance Class | Permissible Deviations for Basic Size Range, in millimetres (mm) | ||||||
| Designation | Description |
0.5 up to 3 |
over 3 up to 6
|
over 6 up to 30 |
over 30 up to 120 |
over 120 up to 400 |
over 400 up to 1000 |
| m | medium |
±0.1 |
±0.1 |
±0.2 |
±0.3 |
±0.5 |
±0.8 |
| Note: For nominal sizes below 0.5mm, the deviations shall be indicated adjuacent to the relevant nominal size(s). | |||||||
Table 2 - Permissible Deviations for Broken Edges (external radii and chamfer heights)
0.5
up to
3
over
3
up to
6
over
6
Tolerance Class
Permissible Deviations for Basic Size Range, in millimetres (mm)
Designation
Description
m
medium
±0.2
±0.5
±1
Note: For nominal sizes below 0.5mm, the deviations shall be indicated adjuacent to the relevant nominal size(s).
Table 3 - Permissible Deviations of Angular Dimensions
up to
10
over
10
up to
50
over
50
up to
120
over
120
up to
400
over
400
Tolerance Class
Permissible Deviations for Ranges of Lengths, in millimetres (mm)
Designation
Description
f
fine
±1˚
±0˚30'
±0˚30'
±0˚10'
±0˚5'
Aboved certain tolerance values is just of the standard tolerances. In case there is a special tolerance requirement for functional reasons, please feel free to contact us to check the possibility.
