Anodizing is a common surface treatment used in many industries, including automotive, aerospace, and medical. It enhances the wear resistance, corrosion resistance, and aesthetic appeal of metal parts. However, anodizing requires the use of a rack or fixture to suspend the parts in the anodizing tank. If the parts are not properly supported or positioned, they may have hanging points, which can result in uneven anodizing, color variation, or even damage to the parts. To avoid these issues, it’s important to follow some guidelines when designing and manufacturing parts that will be anodized at PROTO MFG. In this blog post, we will share some tips on how to avoid leaving hanging points and ensure high-quality anodizing results.

1. Consider the Geometry of the Parts
   The first step in avoiding hanging points is to design the parts with the anodizing process in mind. The geometry of the parts should be taken into account when deciding on the type of rack or fixture to use. Complex shapes, such as parts with deep pockets or holes, may require custom fixtures to hold them securely. In some cases, it may be necessary to modify the design of the part to simplify the anodizing process. For example, adding small tabs or holes can provide multiple attachment points for the rack and reduce the risk of hanging points.
2. Use the Right Material and Surface Finish
   The material and surface finish of the parts can also affect the anodizing process. Aluminium is the most common material used for anodizing due to its ability to form a protective oxide layer. However, the surface finish of the aluminium can affect the adhesion of the anodizing coating. A smooth, even surface is ideal for anodizing, while rough or uneven surfaces can lead to hanging points. To avoid these issues, it’s important to choose the right material and surface finish for your parts and consult with the anodizing experts at PROTO MFG.
3. Consider the Weight and Size of the Parts
   The weight and size of the parts can also impact their ability to be anodized without leaving hanging points. Large or heavy parts may require additional support or a specialized fixture to ensure they are properly suspended during the anodizing process. In some cases, it may be necessary to anodize the parts in sections or batches to avoid overloading the anodizing tank. It’s important to work with the anodizing team at PROTO MFG to determine the best approach for your specific parts.
4. Follow Proper Hanging and Masking Techniques
   When preparing the parts for anodizing, it’s important to follow proper hanging and masking techniques to avoid leaving hanging points or exposing unwanted areas. The parts should be cleaned and dried thoroughly before attaching them to the rack or fixture using appropriate hooks or clips. Care must be taken to avoid creating stress points or contact marks that can affect the anodizing results. Any areas that need to be protected from the anodizing solution should be masked using high-temperature tape or wax. The masking should be precise and uniform to ensure even coating and avoid leakage.
5. Inspect the Anodized Parts for Quality
   After the anodizing process is complete, the parts should be inspected for quality and any hanging points should be identified and addressed. PROTO MFG has trained operators who can perform visual and dimensional inspections to ensure that the anodized parts meet the required specifications. Any defects or issues should be documented and resolved before the parts are shipped to the customer.

In conclusion, anodizing is a valuable surface treatment for metal parts, but it requires careful planning and execution to avoid leaving hanging points that can affect the quality of the final product. By considering the geometry, material, weight, size, and hanging/masking techniques of the parts, and working closely with the anodizing experts at PROTO MFG, you can achieve high-quality anodized parts that meet your specifications and expectations. Contact us today to learn more about our anodizing capabilities and how we can help you with your next project.