2. Type of Anodizing Process
We’d like you to know all the types of anodizing that exist to be aware of options that can be offered. However, we cannot provide you with actual costs, but only with assumptions which of the processes are more or less expensive. It is so because we have seen prices for different types of anodizing significantly vary from seller to seller.
Type I or Chromic Acid Anodizing (CAA).
Chromic acid provides the thinnest anodizing coat, up to +/-0.0001.” However, it is not recommended for aesthetic purposes because it absorbs dyes.
Continued use of chromic is a crucial environmental concern. That is why costs are tightly linked to a particular region’s policy regarding chromic acid. Costs for this process are rather average.
Boric-Sulfuric Acid Anodizing (BSAA).
You may be offered to anodize your parts with boric-sulfuric acid instead of chromic acid. It creates a less precise coating, but it can be used as a paint/prime base. It is also more energy-efficient than the Type I process. Thus, the price for BSAA is most likely lower than for CAA.
Type II or Sulfuric Acid Anodizing.
This process is the most widespread one. It offers great precision, up to +/-0.001”, and great corrosion resistance. It absorbs dyes well and is receptive to other methods of finishing.
The kicker is that sulfuric acid anodizing is less expensive than other anodizing types. It is so because of less heat and power consumption, absence of safety implications, and more affordable acid used.
If you are completely unsure that anodizing would be a good fit for your components, we suggest sulfuric acid anodizing. Unless specifications directly demand something different, of course.
Type III or Hard Anodizing (Hardcoat).
This process also exploits sulfuric acid-based electrolytes. However, the coating obtained is much thicker and denser. You would really need hard anodizing if your components were expected to be subject to extreme wear applications.
The good thing is that hard coated parts can be black dyed and have a nice appearance. They are also non-conductive (circumstantial features).
Typically, hard anodize is somewhere between type I and type II anodizing, concerning the price. Unfortunately, you do not have much of a choice if you need superior abrasion and corrosion resistance.
Titanium Anodizing.
This one is attributed to coating titanium parts alone. It is simply the controlled creation of an oxide film on the metal workpieces’ surfaces.
Other methods of anodizing are suitable, mostly for aluminum. So, one more time, you do not have a broad range of options of how to apply coating on titanium, but this one.
Luckily, it is not that expensive. Additionally, several features with which titanium anodizing can enhance the surface, which enables it to be compared to any other type of coating.
