USA Investment Casting Linear Tolerance (ICI, USA)
Nominal Dimension |
General |
Premium |
inch |
mm |
inch |
mm |
inch |
mm |
up to 1/2 |
≤12.70 |
±0.007 |
±0.18 |
±0.003 |
±0.08 |
up to 1 |
≤25.40 |
±0.010 |
±0.25 |
±0.005 |
±0.13 |
up to 2 |
≤50.80 |
±0.013 |
±0.33 |
±0.008 |
±0.20 |
up to 3 |
≤76.20 |
±0.016 |
±0.41 |
±0.010 |
±0.25 |
up to 4 |
≤101.60 |
±0.019 |
±0.48 |
±0.012 |
±0.30 |
up to 5 |
≤127.00 |
±0.022 |
±0.56 |
±0.014 |
±0.36 |
up to 6 |
≤152.40 |
±0.025 |
±0.64 |
±0.015 |
±0.38 |
up to 7 |
≤177.80 |
±0.028 |
±0.71 |
±0.016 |
±0.41 |
up to 8 |
≤203.20 |
±0.031 |
±0.79 |
±0.017 |
±0.43 |
up to 9 |
≤228.60 |
±0.034 |
±0.86 |
±0.018 |
±0.46 |
up to 10 |
≤254.00 |
±0.037 |
±0.94 |
±0.019 |
±0.48 |
Normal tolerances can be expected for production repeatability of all casting dimensions. As a general rule, normal linear tolerance on an investment casting can be + .010" for up to 1", add + .005" for each additional inch thereafter.
Premium tolerances require additional operations at extra cost and achieve closer tolerances on selected dimensions only. Premium tolerances should be determined during consultation with our engineer.
Linear Tolerance of Germany Investment Casting Institute VDG P690
Nominal dimension |
Length , width , height (mm) |
D1 |
D2 |
D3 |
>
from |
≤
To |
公 差
Tolerance |
公差带
field |
公 差
Tolerance |
公差带
field |
公 差Tolerance |
公差带
field |
0 |
6 |
±0.15 |
0.30 |
±0.12 |
0.24 |
±0.1 |
0.2 |
6 |
10 |
±0.18 |
0.36 |
±0.14 |
0.28 |
±0.11 |
0.22 |
10 |
18 |
±0.22 |
0.44 |
±0.17 |
0.34 |
±0.14 |
0.28 |
18 |
30 |
±0.26 |
0.52 |
±0.20 |
0.4 |
±0.17 |
0.34 |
30 |
50 |
±0.4 |
0.8 |
±0.31 |
0.62 |
±0.25 |
0.5 |
50 |
80 |
±0.45 |
0.9 |
±0.37 |
0.74 |
±0.3 |
0.6 |
80 |
120 |
±0.55 |
1.1 |
±0.44 |
0.88 |
±0.35 |
0.7 |
120 |
180 |
±0.8 |
1.6 |
±0.65 |
1.30 |
±0.5 |
1.0 |
180 |
250 |
±1.2 |
2.4 |
±0.95 |
1.9 |
±0.75 |
1.5 |
250 |
315 |
±1.3 |
1.1 |
±1.0 |
2.0 |
±0.8 |
1.6 |
315 |
400 |
±1.8 |
3.6 |
±1.4 |
2.8 |
|
|
400 |
500 |
±2.0 |
4.0 |
±1.60 |
3.20 |
|
|
500 |
630 |
±2.7 |
5.4 |
±2.2 |
4.4 |
|
|
D1: General dimension tolerances
D2: Applicable to important dimensions requiring close tolerances
D3: Premium tolerance require additional operations at extra cost, only applied to a few special dimensions.
Unless otherwise specified the chamfer and radius of corners needn’t inspect generally, Reference tolerance may be ±0.6 for dimensions up to 6mm , add + 0.2 for each additional 6mm.
ISO Linear Dimension Casting Tolerances (ISO8062)
Nominal dimension |
Linear dimension Tolerances |
> |
≤ |
CT4 |
CT5 |
CT6 |
CT7 |
CT8 |
— |
10 |
0.26 |
±0.13 |
0.36 |
±0.18 |
0.52 |
±0.26 |
0.74 |
±0.37 |
1.0 |
±0.5 |
10 |
16 |
0.28 |
±0.14 |
0.38 |
±0.19 |
0.54 |
±0.27 |
0.78 |
±0.39 |
1.1 |
±0.55 |
16 |
25 |
0.30 |
±0.15 |
0.42 |
±0.21 |
0.58 |
±0.29 |
0.82 |
±0.44 |
1.2 |
±0.6 |
25 |
40 |
0.32 |
±0.16 |
0.46 |
±0.23 |
0.64 |
±0.32 |
0.90 |
±0.45 |
1.3 |
±0.65 |
40 |
63 |
0.36 |
±0.18 |
0.50 |
±0.25 |
0.70 |
±0.35 |
1.0 |
±0.50 |
1.4 |
±0.70 |
63 |
100 |
0.40 |
±0.20 |
0.56 |
±0.28 |
0.78 |
±0.39 |
1.1 |
±0.55 |
1.6 |
±0.80 |
100 |
160 |
0.44 |
±0.22 |
0.62 |
±0.31 |
0.88 |
±0.44 |
1.2 |
±0.60 |
1.8 |
±0.90 |
160 |
250 |
0.50 |
±0.25 |
0.70 |
±0.35 |
1.00 |
±0.50 |
1.4 |
±0.70 |
2.0 |
±1.0 |
250 |
400 |
0.56 |
±0.28 |
0.78 |
±0.39 |
1.1 |
±0.55 |
1.6 |
±0.80 |
2.2 |
±1.1 |
400 |
630 |
0.64 |
±0.32 |
0.90 |
±0.45 |
1.2 |
±0.60 |
1.8 |
±0.90 |
2.6 |
±1.3 |
■ General Level ■ Premium Level
Select tolerance level according to maximum outline dimension. Looser level should be selected for hole diameter and wall thickness.
● CASTING GEOMETRICAL TOLERANCE
* Casting Angle Tolerance: ±0.5 º to ±2 º
As-cast tolerances of angles depend on their location in casting. They range from ± 1/2° for well supported positions to ± 2° where inherent distortion could be expected.
* Casting Straightness: 0.005" per inch
Tolerances for axial straightness: ±.005 in. per inch (±.127 mm per 25 mm) as cast.
* Flatness:
Size (mm) |
General Tolerance(mm) |
Premium Tolerance(mm) |
Up to 25 |
0.20 |
0.13 |
25-50 |
0.40 |
0.20 |
50-100 |
0.60 |
0.30 |
100-150 |
0.80 |
0.41 |
* Roundness
"Out of round" is defined as the radial difference between a true circle and a given circumference. It is the total indicator reading when the part is rotated 360۫ or half the diameter difference between the maximum and minimum condition.
Out of Roundness Tolerances (TIR or Half of the Diameter Difference , mm)
Diameter (mm) |
General Tolerance(mm) |
Premium tolerance(mm) |
Up to 25 |
0.20 |
0.15 |
25-38 |
0.30 |
0.20 |
38-50 |
0.40 |
0.25 |
50-75 |
0.50 |
0.38 |
* Concentricity
Centers of I.D. to O.D. will be concentric within 0.08 mm per 13 mm of wall thickness. This disregards out-of-roundness, and assumes measurements in the same plane If the concentricity is being measured in separate planes, the tolerances of straightness above must be added.
● MACHININED DIMENSION TOLERANCE (ISO2768- m )
Nominal Dimension (mm) |
0.5-3 |
>3-6 |
>6-30 |
>30-120 |
>120-400 |
>400-1000 |
Linear Tolerance (mm) |
±0.1 |
±0.1 |
±0.2 |
±0.3 |
±0.5 |
±0.8 |
● REQUIRED MACHINING ALLOWANCES (ISO8062 Class E)
Max dimension (mm) |
> |
0 |
40 |
63 |
100 |
160 |
250 |
400 |
≤ |
40 |
63 |
100 |
160 |
250 |
400 |
630 |
RMA (mm) |
0.4 |
0.4 |
0.7 |
1.1 |
1.4 |
1.4 |
2.2 |
|