Will thermal expansion and contraction cause differences in the tolerances of die-cast lighting parts?

Thermal expansion and contraction do indeed have an impact on the tolerances of die-casting lighting parts, especially in scenarios where high dimensional accuracy is required. The following are explanations from multiple perspectives:

1. Thermal expansion and contraction are physical properties of metal materials
Metals expand when heated and contract when cooled, which is determined by the thermal expansion coefficient of the material itself.
Aluminum alloys and zinc alloys commonly used in die-casting lighting parts exhibit significant thermal expansion behavior.

2. The size may deviate from the tolerance range with temperature changes
In environments with rising or falling temperatures, the length, aperture, thickness, and other dimensions of parts may undergo slight changes.
If the design tolerance is too tight and there is a large temperature difference in the usage environment, it may lead to problems such as poor assembly, jamming, or loosening.

3. Processing and measuring temperature affect actual accuracy
During the production process, if the die-casting parts are measured or processed before they have fully cooled down, the actual dimensions may deviate from the target value due to shrinkage after cooling.
The correct approach is to conduct dimensional testing at room temperature to reflect the dimensional tolerances under actual usage conditions.

4. Inconsistent thermal expansion between different materials may cause assembly stress
Die cast lighting parts are often used in conjunction with materials such as glass, plastic, rubber, etc.
Different materials have different coefficients of thermal expansion. If the design is not reasonable, stress, deformation, cracking, or detachment may occur due to differences in thermal expansion and contraction.

5. Large parts or elongated structures have a more significant impact
Die cast parts with larger volume or slender structure have greater dimensional changes under the influence of thermal expansion and contraction, which puts higher requirements on tolerance control.
It is necessary to appropriately relax local dimensional tolerances or adopt compensatory design during the design phase.

6. The usage environment has guiding significance for tolerance design
Outdoor lighting parts may face temperature differences between day and night or seasonal variations, which require appropriate tolerance zones to be set according to the usage environment during design.
For example, when there is a large temperature difference between winter and summer in the north, it should be considered to leave a larger expansion margin.

7. The impact can be reduced through material selection or structural design
Choosing alloy materials with low thermal expansion coefficient and good thermal stability can reduce the size deviation caused by thermal expansion and contraction.
In terms of structural design, expansion joints, elastic gaskets, or floating connections can be added to reduce thermal deformation stress.