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Basic linear tolerance E1 call outs
represent tolerances on one side of the parting line only. For
dimensions that cross the parting line add E2 to E1. For dimensions
including features in both the mold itself and in core add E3 to E1
and/or E2. The amount of additional tolerance for E2 and E3 is
determined by the projected area of either the casting at the
parting line for E2 or the projected area of the core in contact
with the casting for E3.
For dimensions which cross the parting line, are defined in part by
core or are in some other way additive, these tolerances may require
some expansion. The foundry should be consulted and good judgment is
recommended.
Consult
your foundry for specific information.
|
Basic Linear Tolerance |
(E1) |
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Sand |
Permanent Mold |
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Machined Tooling |
Cast & Polished Mold |
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Up thru 6 in. |
+- 0.030 |
Up through 1 in. |
+- 0.015 |
+- 0.030 |
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Additional each inch over 6 |
+- 0.002 |
Additional each inch over 1 |
+- 0.002 |
+- 0.003 |
|
Additional Tolerance for Cores or Across Parting Lines
(E2 & E3) |
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Projected Horizontal |
Sand Casting |
Permanent Mold |
Permanent Mold |
Permanent Mold |
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Area of Casting or Core |
Parting Line & Core |
Parting Line |
Sand Core |
Metal Core |
|
Up to 10 square inches |
+- 0.020 |
+- 0.010 |
+- 0.015 |
+- 0.010 |
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10 - 50 sq in |
+- 0.035 |
+- 0.015 |
+- 0.025 |
+- 0.015 |
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50 - 100 sq in |
+- 0.045 |
+- 0.020 |
+- 0.030 |
+- 0.015 |
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100 - 250 sq in |
+- 0.060 |
+- 0.025 |
+- 0.040 |
+- 0.022 |
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250 - 500 sq in |
+- 0.090 |
+- 0.030 |
+- 0.050 |
+- 0.032 |
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