General Tolerances ISO 2768-1/JIS B 0405
Apporo Industries Corporation, LTD is a CNC machining service, Taiwan based factory in line with international standard, such as general tolerance ISO 2768 or JIS B 0405. Please refer to the ISO 2768/JIS B 0405 tables below in details.
Table 1 - Linear Dimensions
|
Permissible deviations in mm for nominal size in mm |
Tolerance class designation (description) |
|||
|
f (fine) |
m (medium) |
c (coarse) |
v (very coarse) |
|
|
0.5* to 3 |
±0.05 |
±0.1 |
±0.2 |
- |
|
above 3 to 6 |
±0.05 |
±0.1 |
±0.3 |
±0.5 |
|
above 6 to 30 |
±0.1 |
±0.2 |
±0.5 |
±1.0 |
|
above 30 to 120 |
±0.15 |
±0.3 |
±0.8 |
±1.5 |
|
above 120 to 400 |
±0.2 |
±0.5 |
±1.2 |
±2.5 |
|
above 400 to 1000 |
±0.3 |
±0.8 |
±2.0 |
±4.0 |
|
above 1000 to 2000 |
±0.5 |
±1.2 |
±3.0 |
±6.0 |
|
above 2000 to 4000 |
- |
±2.0 |
±4.0 |
±8.0 |
* For nominal size below 0.5mm, the deviation shall be indicated adjacent to the relevant nominal size(s).
Table 2 - External Radii and Chamfer Heights
|
Permissible deviations in mm for nominal size in mm |
Tolerance class designation (description) |
|||
|
f (fine) |
m (medium) |
c (coarse) |
v (very coarse) |
|
|
0.5* to 3 |
±0.2 |
±0.4 |
||
|
above 3 to 6 |
±0.5 |
±1.0 |
||
|
above 6 |
±1.0 |
±2.0 |
||
Table 3 - Angular Dimensions
|
Permissible deviations in mm for nominal size in mm |
Tolerance class designation (description) |
|||
|
f (fine) |
m (medium) |
c (coarse) |
v (very coarse) |
|
|
0 to 10 |
±1º |
±1º30’ |
±3º |
|
|
above 10 to 50 |
±30’ |
±1º |
±2º |
|
|
above 50 to 120 |
±20’ |
±30’ |
±1º |
|
|
above 120 to 400 |
±10’ |
±15’ |
±30’ |
|
|
above 400 |
±5’ |
±10’ |
±20’ |
|
General Tolerances ISO 2768-2/JIS B 0419
GENERAL TOLERANCES FOR FORM AND POSITION
There are several common requirements for CNC machining services, such like straightness, flatness, perpendicularity, symmetry, run-out, and etc. A machined part may distort, tilt due to various situations:
- Raw material stiffness
- Raw material internal stress
- Poor machining process
- The CNC machine is out of alignment
Therefore, we will have to inspect the machined parts based on ISO 2768-2/JIS B 0419 below.
Table 1 - Straightness and Flatness
|
Ranges of nominal lengths in mm |
Tolerance class |
||
|
H |
K |
L |
|
|
0 to 10 |
0.02 |
0.05 |
0.1 |
|
above 10 to 30 |
0.05 |
0.1 |
0.2 |
|
above 30 to 100 |
0.1 |
0.2 |
0.4 |
|
above 100 to 300 |
0.2 |
0.4 |
0.8 |
|
above 300 to 1000 |
0.3 |
0.6 |
1.2 |
|
above 1000 to 3000 |
0.4 |
0.8 |
1.6 |
Table 2 - Perpendicularity
|
Ranges of nominal lengths in mm |
Tolerance class |
||
|
H |
K |
L |
|
|
0 to 100 |
0.2 |
0.4 |
0.6 |
|
above 100 to 300 |
0.3 |
0.6 |
1 |
|
above 300 to 1000 |
0.4 |
0.8 |
1.5 |
|
above 1000 to 3000 |
0.5 |
1 |
2 |
Table 3 - Symmetry
|
Ranges of nominal lengths in mm |
Tolerance class |
||
|
H |
K |
L |
|
|
0 to 100 |
0.5 |
0.6 |
0.6 |
|
above 100 to 300 |
1 |
||
|
above 300 to 1000 |
0.8 |
1.5 |
|
|
above 1000 to 3000 |
1 |
2 |
|
Table 4 - Run Out
|
Ranges of nominal lengths in mm |
Tolerance class |
||
|
H |
K |
L |
|
|
0.1 |
0.2 |
0.5 |
|
