Isn't "magnesium phosphate" coating otherwise known as "parkerizing?"
Yup..I thought Rick told me black oxide. Either way, I'd rather have parkerizing than bluing..
Manganese Phosphate (Parkerize) is a chemical conversion coating that adds 0.0002 to 0.0003 inches to steel and cast surfaces and provides excellent corrosion resistance. Manganese Phosphate can also be used as a base for subsequent coating or paint. Parkerizing provides superior corrosion resistance, lubricity and resistance to galling. These qualities make for an excellent coating on gears, hand and pneumatic tools, and firearms. Parkerizing is the preferred finish for military weaponry and ordinance. Manganese Phosphate is sometimes referred to as "Luberizing" when using the Parco trade name.
