5 Commonly Used Die Casting Surface Treatment

Several people who are new to the concept of die casting have a misconception that the process is completed once the die is cast. However, the reality is that most of the experienced die casters put in extra efforts and implement a number of surface treatment processes on the finished die to improve its quality and durability.

It is true that the surface treatment process is not a necessary process in the metal shaping process of die casting. Still, several professional die casting companies prefer to carry out this process because they are aware of the fact that these surface treatments can significantly improve the value and quality of the finished product. Some of the most common surface treatment processes implemented by expert die casters are as follows.


Power coat paint or paint is an excellent natural coating for finished die casting components. Die casters usually apply power coat paint or ordinary paint to a non-treated or pre-treated metal surface. This enables them to make the metal surface or the finished product a lot more appealing without compromising the quality or value of the component.

Aluminum Passivation

Aluminum passivation, which is also known as conversion coating is also applied to the surface of finished die cast parts. However, this coating is most commonly used for aluminum die casting components. This thin aluminum film prevents the finished die part from corrosion without dampening its conductivity properties.


Die casters usually implement three different kinds of anodizing treatments on a finished die. Chromic acid anodizing also called as Type I anodizing is the most widely used process. This process involves the use of toxic chromic acid and consequently, it is used only for the finished die parts that require maximum corrosion resistance.

Casting Impregnation

Some level of porosity cannot be avoided during metal casting and the presence of small pores can be ignored, as they do not affect the die’s structural integrity. However, if you want your finished die part to be pressure tight and absolutely solid, then die casters will implement the process of casting impregnation. This process efficiently seals in the pores and makes the die a lot more solid and pressure tight.


E-coat process implements the use of electric current in order to deposit the paint. This process offers more corrosion protection to the finished die and it also a lot cheaper when compared to other painting options listed above.