Dimensions & Tolerances
1.Dimensional Tolerance
| Range of Dimension(mm) | Commercial Tolerance (%) | Critical Tolerance (%) |
0 10 |
±0.25 | ±0.1 |
| 1025 |
±0.15 | |
| 2550 |
±0.4 | ±0.25 |
| 5075 |
±0.8 | ±0.4 |
| 75100 |
±0.5 | |
| More than 100 | ±1% | ±0.5% |
In order to secure accuracy of product dimensions we shall provide for a commercial tolerance. If you would need more accuracy than a commercial tolerance you will be able to increase it up to a critical tolerance through truing of the mold, However, the cost of the mold will be proportionally increased if the number of locations needing critical tolerances is large.
2.Angle Tolerance
| Angle | Commercial Tolerance | Critical Tolerance |
| α | ±30’ | ±20’ |
| β | ±2° | ±30° |
| γ | ±2° | ±1° |
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3.Tolerance for Flatness and Straightness
| Length(mm) | Commercial Tolerance(mm) | Critical Tolerance(mm) |
| Less than 25 | 0.2 | 0.1 |
| 2550 |
0.4 | 0.15 |
| 50100 |
0.6 | 0.25 |
| 100150 |
0.8 | 0.40 |
Above table shows normal values of the product except the special parts with big wall thickness. The depression(凹) of a flat level will vary depending on size of the area and wall thickness.
4.Minimum Wall Thickness
| Items | Normal (mm) | Under optimum conditions (mm) |
| Ferroalloy | 1.30 | 0.5 |
| Nonferrous metal alloy | 1.00 | 0.5 |
The wall thickness more than 2 mm is preferable though it will vary depending upon the surface area and the shape.
Design
1.Limitation of Size and Weight
| Description | Preferable (mm) | Possible range (mm) |
| Weight | Less than 3 kgs | Less than 20 kgs |
| Dimension | H150xW150xD250 | H350xW450xD450 |
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2.Surface Roughness
| 618S |
3.Ditch
 d 2w at  >2w and w>3.02w at d>2wMinimum width of ditch= 1.3 (d<1.0) |
4.Hollow
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5.Design of Lost Wax
 To change a wall thickness for smoothness |
 To unify a wall thickness, to put "R" inside angle |
 To avoid a sharp edge |
 To avoid a partial wall thickness |
 To reduce the weight and to put "R" so as to avoid bruises |
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 To thin the wall thickness gradually from Gate to end |
 To simplify formwork disassembling and to design not to use inside lost wax so as to save the mold and tolling cost. |
 Designing a flat surface of Gate is more preferable than curved surface in view of quality and cost performance. |
 To consider "W" part to increase the process efficiency R  0.5W 2RU W/2 |
 Possible to open a long span hollow if you will form a casting mold reinforcing hole in a horizontal line. |
 To open horizontal hole in the ditch with narrow width and deep depth. |