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SULFURIC ANODIZE:  {Type II Coatings}The Most Commonly Prescribed Surface Finish on Aluminum, Conventional "ANODIZE" is formed by an Electro-Chemical Process that produces a layer of Aluminum Oxide.  Time cycles vary from 30 to 60 minutes depending on Alloy and Desired Appearance. 

• Good Corrosion Resistance (336 hrs salt spray)
• Improved Wear and Anti-Galling Properties. 
• Can be dyed to a variety of colors. 
• Electrical Insulation Properties

Anodized surfaces are normally "sealed" to improve corrosion resistance, and/or lock in dyes.  RCI offers the following Seal Options: Hot Water, Teflon, Nickel Acetate, and Sodium Dichromate.

SPECIFICATIONS and CERTIFICATIONS:  The Formation and Properties of Anodize Finishes are described in the "Controlling Document", Mil-A-8625.  All other Customer Specs follow the format and guidelines of those documents. These are Designated as:

• Chromic Acid Anodize:          Type I
• Sulfuric Acid Anodize:            Type II
• Hardcoat Anodize:                  Type III
•   EACH of these "types" are then sealed
•                  Non-Dyed Seals                Class 1
•                  Dyed Seals                        Class 2

Therefore, "Type II, Class 2" call out specifies a part that is Sulfuric Anodized and then Dyed.

Additional Technical and Engineering information is available at the following "Aluminum Anodizer's" site, http://www.anodizing.org//what_is_anodizing.html