The ultimate success of the casting design depends on the communication between the designer and foundry engineers. When the foundry is properly informed of part requirements, there is usually a compromise of specifications that will allow for maximum compliance to print specifications and finish part design.
1.Standard Linear Tolerance(mm)
Dimensions |
Normal |
Premium |
Up to 10 |
±0.12 |
±0.10 |
10 to 15 |
±0.20 |
±0.13 |
15 to 20 |
±0.25 |
±0.15 |
20 to 30 |
±0.30 |
±0.20 |
30 to 50 |
±0.40 |
±0.25 |
50 to 75 |
±0.50 |
±0.35 |
75 to 100 |
±0.65 |
±0.45 |
100 to 125 |
±0.80 |
±0.60 |
125 to 150 |
±1.00 |
±0.70 |
150 to 175 |
±1.20 |
±0.80 |
175 to 200 |
±1.50 |
±0.90 |
200 to 250 |
±1.80 |
±1.10 |
over 250 |
±0.80% |
±0.50% |
2.Angularity
As-cast tolerances of angles is mainly a function of the part design and their ocation in casting. They range from +/- 1/2 degree (considered minimum) for well supported positions to +/- 2 degree where existing distortion could be expected. Inclusion of gussets and ribs normally minimizes distortion and many sections can be mechanically straightened.
3.Flatness, Strengteness and Roundness
Section Thickness |
Possible Thickness Section Sink per Face of Casting |
Normal |
Premium |
Up to 25 |
0.20 |
0.10 |
25 to 50 |
0.40 |
0.20 |
50 to 100 |
0.60 |
0.30 |
100 to 150 |
0.80 |
0.40 |
Straightening adds cost, but sometimes cannot be avoided. The actual straightening costs are often dependent on the tightness of the tolerance specified, so do not specify tighter flatness, straightness, roundness, or other requirements than you actually require. (Lianchuang typically straightens parts using die sets that will be included in your tooling price.)
4.Size and Weight Range
Size and Weight. Part size and weight are the most critical factors in determining part cost because mold capacity is limited by both size and weight. The more pieces that can run on a mold, the lower the part cost. Unnecessary mass should always be removed by correct engineering practices to reduce part weight.
Items |
Size |
Premium |
Outline Dimention |
1000×620×380 |
up to 100 |
Weight(kgs) |
0.001-60 |
0.10 to 1.50 |
Min. Wall Thickness |
0.50 |
5 to 10 |
5.Surface Roughness
80 to 120 RMS are average.
6.Hole Length
Making a good hole in a casting is dependent on the integrity of the shell. The ratio of holediameter to length is important in determining what can be offered. Blind holes must have aradius at the top and the bottom of the hole to insure that a strong core is built for castingpurposes and to insure the best possible casting
Hole Type |
Size Range |
Length to Dia.Ratio |
Thru |
2 to 3 |
≤2 |
|
4 to 7 |
≤5 |
|
≥8 |
≤10 |
Blind |
2 to 3 |
≤1 |
|
4 to 7 |
≤2.5 |
|
≥8 |
≤3.5 |
Other information, please contact us.
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