864.990.0762 inquiries@buntyllc.com 444 Fairforest Way, Greenville, SC, 29607, US
High-Quality products
High-quality metal components.
Unbeatable customer service
Highest possible level of service
Get A Quote

Manganese Phosphate Coating

Manganese Phosphate Coating

Metal part manufacturers frequently perform surface treatments to modify the exterior properties of components in a desired functional or decorative way.

The application of one (or more) surface coating formulations represents a popular type of surface treatment. The manufacturer applies a coating to a workpiece in order to modify the surface in the desired manner. Several types of phosphate coatings have gained popularity.

Phosphate Coating

Today, abrasive phosphate coatings made from phosphate, iron, or zinc phosphate salts have gained widespread use within the commercial industrial parts marketplace.

When applied to some types of metal workpieces, these coatings may serve as primers that help prepare the surface for the application of paint. They may also help roughen the surface prior to the application of sealants and lubricants.

About Manganese Phosphate Coating

Manganese phosphate coatings fall into the category of metal surface pre-treatment applications. They enable manufacturers to prepare work pieces for the application of sealants or paints which will enhance corrosion resistance.

Manganese phosphate coatings hold particular value in the preparation of mechanical components subjected to frictional forces during daily use. In some cases, manufacturers apply manganese phosphate coatings to threaded components intended for use within an assembly to reduce the incidence of chafing.

Industrial manufacturers may completely immerse surfaces for treatment within liquid baths of phosphorous salts. They prepare the workpiece by first rigorously washing the metal surface to remove greasy deposits and debris.

Many companies will also soak parts in mineral oil to remove rust prior to this surface application. They then rinse the part and completely submerge it in the bath, usually at a temperature of slightly over 200 degrees Fahrenheit.

After immersion for a designated period of time, the surface of the metal part will roughen sufficiently to permit it to retain layers of sealant and/or paint. This change occurs because the solution in the bath reacts chemically with the surface of the metal to allow the formation of crystalline phosphates.

In some cases, manufacturers dry parts in ovens following the application of the manganese phosphate coating and subsequent rinsing. They then coat the part with desired sealants, paints and lubricants.

Manganese (II) phosphate, an inorganic compound, carries the chemical formula Mn3(PO4)2. Phosphorous often combines with iron in nature within mineral ores.

The process of applying manganese phosphate coatings seeks to utilize manganese phosphate formation within a controlled industrial context to help coat ferrous metal alloys and supply extra protection against wear.

Apparently, some manufacturers refer to the manganese phosphate coating as an ionized compound of magnesium, manganese (III) phosphite, or MnPO3.

Manufacturers also apply manganese coatings in an effort to obtain better corrosion resistance and reduce galling in threaded parts.

Manganese Phosphate Coating: Materials And Applications

Phosphate coatings today enjoy widespread use in many places around the world. Reliance on these types of surface coatings enables manufacturers to complete finishing steps intended to enhance the competitiveness of their products in the global marketplace.

Widely available constituent materials have likely contributed to the popularity of these coatings. Additionally, metals treated in this manner have obtained numerous commercial applications.


Manufacturers have learned to pretreat a number of different metals and metal alloys with phosphate coatings.

Frequent raw materials for manganese phosphate coatings reportedly include many different ferrous alloys. This type of industrial coating process typically requires the use of immersion baths.

Industrial manufacturers who utilize a manganese phosphate coating additionally usually need a heating source and a system for controlling and monitoring applicable parameters of the surface treatment process (such as the temperature of the bath).

They may also require facilities for cleaning, rinsing, and baking metal workpieces. The use of salt baths also necessitates consideration of environmental cleanup issues by manufacturers who provide manganese phosphate coating services.


The use of manganese phosphate coatings has gained wide use within a number of economic sectors.

Firearms and munitions manufacturers, industrial equipment manufacturers, the aerospace industry, the oil and gas industry, and the transportation industries have all utilized this technology during the finishing of metal parts or equipment in the past.

Applying sealants and paints to ferrous materials helps extend the useful lifespan of many types of metal products and machine components.

Some examples of products that often receive this type of surface treatment include the screws, nuts, washers, bolts, and gears utilized within engines.

Ball bearings also reportedly sometimes benefit from manganese phosphate coating. Additionally, numerous firearms manufacturers perform this process prior to applying sealants to their products.

Advantages of Manganese Phosphate Coating

Manganese phosphate coating offers some important advantages in certain settings. Metal parts manufacturers utilize these surface treatments for several reasons.

1. By promoting the roughening of the surface of metal parts, manufacturers can essentially help prime these locations to accept sealants and paints more effectively.

Without this pre-treatment, consumers may need to re-apply other coatings on a more frequent basis in order to help protect the surface against corrosion and heavy wear.

2. By enabling manufacturers to apply sealants and paints, manganese phosphate coatings contribute value to the metal part, ultimately increasing the competitiveness of some products commercially.

If given the choice between selecting a pre-treated and an untreated metal part, for example, many buyers choose components that have already undergone manganese phosphate coating.

3. To some extent, the use of manganese phosphate coatings also impacts the final appearance of a ferrous metal part. Even when a manufacturer does not apply sealants to the surface, this pre-treatment may change the part’s exterior appearance and harden threaded components against damage from galling and chafing during heavy use.


Bunty LLC is a manganese phosphate coating supplier. For further information about our manganese phosphate coating services, contact us via the convenient website form or submit a request for quote directly.

We welcome your inquiries. 

About us

From a contract manufacturing firm, BuntyLLC evolved into a full service custom machined, forged and cast metal parts fabrication enterprise. We supply global solutions from our headquarters in Greenville, South Carolina.

Get A Quote