Casting Tolerances
Functional Dimensions |
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Inches |
Millimetres |
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Dimension |
Tolerance |
Dimension |
Tolerance |
Up to 0.500 |
±.004" |
Up to 12.0 |
± 0.10mm |
Up to 0.500 |
±.006" |
12.0+ to 25.0 |
± 0.15mm |
1.000+ to 1.500 |
±.008" |
25.0+ to 37.0 |
± 0.20mm |
1.500+ to 2.000 |
±.010" |
37.0+ to 50.0 |
± 0.25mm |
2.000 + to 2.500 |
±.012" |
50.0+ to 62.0 |
± 0.30mm |
2.500+ to 3.500 |
±.015" |
62.0+ to 87.0 |
± 0.35mm |
3.500+ to 5.000 |
±.018" |
87.0+ to 125.0 |
± 0.45mm |
5.000+ to 7.500 |
±.021" |
125.0+ to187.0 |
± 0.53mm |
7.500+ to 10.000 |
±.024" |
187.0+ to 250.0 |
± 0.60mm |
10.000+ to 12.500 |
±.027" |
250.0+ to 312.0 |
± 0.68mm |
12.500+ to 15.000 |
±.030" |
312.0+ to 375.0 |
± 0.75mm |
Each additional inch add ± .001" |
Each additional 25mm add ± .025mm |
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Non-Functional Dimensions |
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Where design parameters permit the above tolerances should be increased by 50% |
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Wall Thickness Tolerance
Special tolerances apply to wall thicknesses. The normal tolerance to be allowed is ± .008" (±0.20mm)
Large plain wall sections, above 75sq inches (500sq cm), should incorporate a tolerance of ±0.012" (±0.3mm)
Straightness/Flatness Tolerance
±0.004" (±0.10mm) per inch (per 25mm) excluding localised wax pattern depressions.
Angular Tolerance
±1/2°
Surface Finish
Typical surface finish - 80/100 microinches (2.0/2.5 micrometres). A finer surface finish is generally attainable when specifically requested.
Geometric Tolerances
Are dependant on the casting configuration and/or alloy specification, and would be discussed on an individual basis at the quotation stage.
