Induction shrink-fitting is used for insertion of one metal part into a second metal part. The second metal part is heated just enough that the metal slightly expands, allowing easy insertion of the first part. Once cooled, the parts cannot be separated without significant force, or by reheating and reversing the process.
Induction shrink fitting is used for insertion of one metal part into a second metal part. The second metal part is typically heated between 302°F (150°C) and 572°F (300°C). This causes the part to expand enough to allow for insertion or removal of another component. Typically the low temperature range is used on metals such as aluminum and the higher temperatures are used on metals such as low/medium carbon steel. The process avoids changing the material properties of the metal while allowing the components to be worked.
When inserting a component in a shrink fitting application, we can heat the part slowly to achieve the desired expansion. However, when removing a component, it’s important to heat the outside part quickly. This ensures that the heat does not have the opportunity to penetrate to the component, which would also cause it to expand. Typical applications for shrink fitting include:
- Gear housing assemblies
- Bearing assemblies
- Precision tools
Common materials used in shrink fitting include aluminum, carbon steel, and carbide.