While the actual Mil C 26074 was initial canceled, it has been re-activated with some revisions and alternative standards. It is widely used in the finishing industry, along with both ASM and ASTM standards that also apply to electroless nickel plating in various thicknesses and with a variety of different alloys.
There is a lot of confusion in different industries because of the various cancellations, reinstatements, replacements and redirections to other standard. As with any project requiring production standards to military specifications, working with a metal finishing company that is using the latest, accurate standards is always going to be an important consideration, and definitely a question that should be asked when consideration any metal finishing company.
Classes in the Standard
There are four different classes recognized in the standard. These include:
- Class 1 – coated
- Class 2 – heat treatable base metals such as steel that are hardened through the process
- Class 3 – non-heat treatable base metals such as aluminum
- Class 4 – heat treatable base metals such as aluminum alloys that will have an improved level of nickel deposit adhesion through the process
There are also three grades which are based on both thickness as well as the type of alloy.
The actual processes used in the Mil C 26074 will depend on the Class of the coating, the heat and the time in the processing. This is often called “baking” and depending on the class it can range from one hour to over three hours and at lower to higher temperature depending on the alloy.
When to Use
In all applications and for all indicated Classes and Grades, Mil C 26074 is used when the finished surface has to be hard as well as smooth. This process allows for highly uniform plating to very tight tolerances even on the most irregular surfaces and complex and intricate shapes, which is why it is so important in many different industry applications.
This is the most often requested finishing requirement on parts that will be used at high temperatures and in demanding environments. It is also ideal for building up resistance to corrosion and wear, but the specifics of the process will dictate the properties for the final parts and components.
This is a very common coating process used on parts and components used in the aerospace industry. In addition to tight tolerances and a very uniform coating provided even on the most complex shapes, this coating offers an aesthetically pleasing metallic final surface look that is naturally free from edge accumulation so problematic with other coating options.