Dimensions & Tolerances

1.Dimensional Tolerance

Range of Dimension(mm) Commercial Tolerance (%) Critical Tolerance (%)
010 ±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°


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
 

2.Surface Roughness

618S

3.Ditch

d2w at >2w and w>3.0
2w at d>2w
Minimum width of ditch= 1.3 (d<1.0)

4.Hollow


Non hollow through
2.0D5.0 HDx1.0
5.0<D10.0 HDx1.5
10.0<D HDx3.0

Hollow through
2.0D5.0 HDx3.0
5.0<D10.0 HDx5.0
10.0<D HDx6.0

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
 

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
R0.5
W2R
UW/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.
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