Anodize offers an inexpensive option for those looking to protect their aluminum pieces and can be dyed a multitude of colors for those interested in aesthetics.
Anodizing is an electrolytic process that creates a protective oxide layer on predominantly aluminum material. This is done through a process of current passing through cathodes while the part itself is acting as the anode. MIL Spec 8625 is the guiding specification for this process.
The most common types of anodize are listed below
Chromic Anodize (MIL-A-8625)
Referred to as Type I anodize or Type IB (Low voltage process). Chromic anodize is dark gray in color or can be dyed black. Chromic Anodize has a thin coating (usually less than .0001”), although don’t be fooled by the thin layer, Chromic Anodize has equal corrosion protection as Sulfuric Anodize and Hard coat Anodize.
Chromic Anodize is most commonly utilized in the Aerospace and machining industries. Parts that require strict dimensional tolerances, welding or bonding are generally suitable for the Chromic Anodize process.
Sulfuric Anodize (MIL-A-8625)
Referred to as Type II anodize or Type IIB (Low voltage) is the most frequently utilized type of anodize. Sulfuric’s versatility makes it suitable for a wide range of applications. Due to its porous oxide layer, sulfuric anodize holds dye extremely well. These characteristics make sulfuric the choice for aesthetic purposes in industries such as design, architectural, mechanical and electronics.
It is also commonly used when resistance to abrasion and hardness is required because it is a harder anodize. Nassau Chrome has the capability of performing Grey
(No dye), Red
Anodize. All sulfuric anodize parts that get dyed must be sealed to prevent color loss. If there is a particular color you would like us to match please provide a sample with your parts.
Hard coat Anodize (MIL-A-8625)
Referred to as Type III deposits the most build up (starting at .001”), this anodize is generally requested when parts are subject to strong corrosive environments or extreme wear resistance. Hard coat anodize is generally grey or charcoal in color. At times hard coat can be dyed although the colors tend to be uneven and not particularly attractive. Since hard coat anodize can be built up to several thousandths in some cases, machine shops often look to hard coat to correct mis-machined parts.