Parkerized Definition
Since 09-25-05
http://www.calvan.com/html/what_is_parkerizing.html
Parkerizing or Phosphating is a metal
finish that really gained in popularity during WW2 when the US Government was
looking to replace the typical blued finish on most small arms with a Rust
Resistant and Anti Reflective coating that would be both Durable and Abrasion
Resistant and hold up in all weather extremes, for this they chose Parkerizing
or Phosphating.
The Parkerizing technique is a Phosphate etching process that produces a hard
Matte or Dull finish that is both very Durable and Anti Reflective and with
excellent oil holding properties.
The most commonly types used are the original WW2 type, known as Grey Oxide and
the latter Black Manganese, still in use by many Military and Civilian
Manufacturers in many countries on a wide variety of products.
The standard Grey Oxide may range from light grey to a darker grey depending on
the type and hardness of the metal it is being applied to, whereas the Black
Manganese will usually always be in the Charcoal Black category.
Either type of Parkerizing Finishes will offer much more protection from harsh
weather than bluing, and is very simple to apply and maintain.
Parkerizing is much easier to use than bluing because as it is a Matte Finish
the parts or items you want to Parkerize do not have to be polished, they can be
acid dipped, sanded, bead blasted or sand blasted. In fact a lot nicks and
scratches that would show up on a blued item would not even be seen after
Parkerizing.
Parkerizing is an immersion process requiring the solution to be heated to
approximately 190-210 degrees and the dipping time can range from 5-45 Minutes
or so, depending on the hardness of the metal and the desired thickness of the
coating.
It can be used on any type of Mild or Gun steel, it is not for use on Stainless
or any types of Aluminum.
Parkerizing is sometimes referred to
as black oxide, however this is a misnomer as black oxide is nothing more than a
type of black bluing which does not offer the protection and corrosion
resistance of a parkerized part