We offer a wide range of plating finishes as indicated by the following list. We have included some general information, but please contact us to answer questions related to your specific needs.
Anodizing, Chromic Acid
MIL-A-8625 Type I, Class 1 and AMS 2471
Chromic Acid Anodizing is an industrial, functional finish. Because of the toxic nature of hexavalent chrome, this type of anodizing is being replaced with a sulfuric anodizing whenever it is allowable. The aerospace industry is the largest user of chromic acid anodizing today. Chromic acid anodizing has three advantages over sulfuric acid anodizing:
- The coating thickness is very thin thus making it easier to hold close tolerances. The average coating buildup is 0.000050″ thick.
- Chromic Acid anodizing introduces less stresses into the material than sulfuric acid anodizing.
- Chromic acid is not as detrimental to the aluminum as sulfuric acid; therefore parts with complex shapes that trap the anodizing solution are not attacked in the areas where the acid is trapped.
Chromic acid anodizing is a gray color and because of the thin coating thickness, it is not easily dyed. Even under the best circumstances, a part which is dyed black will have a very grayish appearance.
Anodizing, Hard
Teflon post treatment available.
MIL-A-8625 Type III, Class 1 & 2 and AMS 2469
Hard anodizing is an electro-chemical process which produces an aluminum oxide coating on the aluminum surface. Hard anodizing is specifically used to increase the abrasion resistance of aluminum. The coating is very hard and machinists’ are not excited to drill through the coating or clean up threads which don’t fit after anodizing. The thickness is typically 0.0018″ to 0.0022″. The build up is 1/2 the anodize thickness since the anodizing penetrates the surface of the aluminum.
In order to keep the hard anodizing as hard as possible, it is not sealed unless instructions are given to do so. In order to increase the corrosion resistance of hard anodize, it can be sealed in DI water, nickel acetate or sodium dichromate. The sealing will decrease the hardness of the coating.
Our process is a standard hard anodize process which turns the aluminum dark as the coating gets thicker. It can be dyed black, but other colors show very poorly in the dark background.
All anodized parts must have a contact to the base aluminum; therefore, it is common to have a rack mark. The size of the rack mark will depend on the size and geometry of the part. Please call to discuss the rack mark if you have concerns.
Frequently Asked Questions:
Q: What aluminum alloys may be difficult to hard anodize?
A: Aluminum alloys are not a homogeneous mixture. Foundry procedures and cooling times can cause pockets of metals in the alloy. 2000 series aluminum can have some pockets of copper and these are places where the part can possibly burn because the electrical resistance is lower. 7000 series aluminum can get blisters in areas where zinc accumulated.
Q: What should I do with threads?
A: Unless you cut the threads to accept the anodizing thickness, threads should be plugged or covered to keep them from being anodized. Remember the pitch diameter changes four times the build-up per surface. Also take into account that more anodizing will build-up on the peak of the thread than in the valley.
Anodizing, Sulfuric Acid
Bright dip, clear and colored finishes
MIL-A-8625 Type II, Classes 1 & 2 and AMS 2471
The thickness of this anodize process is normally between 0.0001″ and 0.0006″ thick. The build-up is 1/2 of the total thickness since 1/2 of the anodizing layer penetrates the base metal. The aluminum oxide makes the surface of the aluminum harder and it keeps the naturally occurring oxide from rubbing off the aluminum onto your hands. Extra corrosion protection comes from the sealer which is applied after the anodizing by placing metal salts in the pores of the oxide coating.
The anodize coating can be dyed colors using dyes. A rainbow of colors are available and we typically have these basic colors readily available: black, red, green, gold, violet, brown & blue. It should be noted that these organic dyes will fade from UV radiation in sunlight.
Frequently Asked Questions:
Q: Why did my black fade to purple in a few weeks?
A: The quality of the dye used and the quality of the sealer after the dye will keep the colors from fading. We only use the highest quality dyes and we seal all our parts with a hot nickel acetate solution for the highest quality colors.
Q: Why are some of my parts different colors after a clear anodizing?
A: Different alloys of aluminum will anodize a different color, so the end product will also look different even if the part is dyed. To keep the colors the same, use consistent lots of aluminum alloys.
Q: How far will the anodizing go into a hole?
A: A general rule of thumb is that the anodizing will stay a consistent thickness into a hole, the distance of the hole diameter. The anodizing will then begin to get thinner as the hole goes back further.
Blasting
We offer glass bead, aluminum oxide and plastic media blasting. The plastic media is generally used for paint removal. The glass beads and aluminum oxide media are used for cleaning and applying a specific matte finish on the part before plating.
Black oxide
Featuring both cold and hot applications for Steel and Stainless steel.
MIL-C-13924 and AMS 2485
Black Oxide is a surface treatment which forms an oxide coating on the surface of steels and stainless steels which is black. It’s main application is to change the color of the steel without risk of chipping or peeling where a coating of oil is permissible. Black oxide has no corrosion protective properties on it’s own, but it does make a superior surface for the application of oil to keep the surface from rusting. Common uses for black oxide are tooling, small screws for consumer goods, engine parts and firearms.
The hot black oxide treatment is a better black oxide coating in both function and appearance; however, when the part does not fit into the processing bath, the cold process is a good alternative.
Our process for stainless steels works best for with 300 series stainless.
Frequently Asked Questions
Q: Does Black Oxide have a thickness or buildup?
A: No. Black oxide is a surface treatment only and does not have thickness or buildup.
Q: Is it possible to black oxide other metals then steel and stainless steel?
A: Yes. There is a black oxide treatment for copper and copper alloys.
Q: How scratch resistant is black oxide?
A: Black Oxide is fairly scratch resistant, more so than a black chromate on zinc plating.
Black Zinc Plating
We offer superior quality and beauty of finish for both barrel and racked parts.
Black zinc plating is a zinc eletroplating with a black chromate applied as a post treatment. Black zinc is a popular corrosion resisting finish for steel. The advantages of black zinc over other ways to blacken steel are many. Black zinc is a corrosion resistant coating whereas a black oxide coating is not. Black zinc is much thinner than a black paint or powder coating. The main disadvantage of black zinc is that it does scratch fairly easily.
The best black chromates are still made with hexavalent chromium which means it is not RoHS compliant. There are black dyes and trivalent processes available; however, they are not as cosmetically pleasing and they are much more difficult to control for proper application. We do have a trivalent black chromate available for limited applications.
The black chromate can have a slight iridescence or some colors of the rainbow in the black color. It is also possible to barrel plate using the black chromate but the finish will not be as cosmetic because the parts are hitting one another and leaving some scratching.
Brass Plating
Polish – Antique – Satin
Brass plating is an electro-chemical process which deposits a thin layer of brass (copper-zinc alloy) on metal. Brass is typically used for decorative purposes over a layer of nickel. Plated brass should always be coated with a lacquer to keep the brass from tarnishing. Because the coating is thin if one tried to polish a brass plated item, the brass would be easily removed.
We plate a wide range of household items. Some new, but a majority of the items are being refurbished. This includes heat registers, door hardware, bathroom accessories and cabinet hardware.
When we refurbish old items we typically go through the following steps:
- We remove the old lacquer or paint.
- We remove the old plating.
- We brush or polish the base metal.
- We copper, nickel, or brass plate the item.
- We lacquer the item.
It should be noted that brass plating is not an ideal finish for bathroom fixtures, because the lacquer will degrade with use. Hot liquids, soaps and cleaners soften the coating and will allow the brass underneath to tarnish. Brass lacquered items should only be cleaned with a damp, soft cloth. Some furniture wax can also be applied to the lacquer to help prolong the life.
“Forever brass” which is now applied to plumbing fixtures is a much superior product. It is actually a Zirconium Nitride Physical Vapor Deposition (PVD) coating which is applied in a vacuum. These finishes are far superior to lacquered coating in resisting corrosion on bathroom fixtures. Unfortunately these coatings are not widely available for job shop applications. PVD coating is done primarily on stainless steel and chrome plated surfaces.
Cadmium Plating
Yellow, Clear, Olive Drab chromates
QQ-P-416 all Types & Classes and AMS 2400
Cadmium plating is a process which electro-chemically deposits a thin coating of cadmium on a base metal. It’s primary purpose is corrosion resistance, lubricity, conductivity and solderability. Most aircraft fasteners are cadmium plated for the corrosion resistance and lubricity. Electrically conducting parts are sometimes plated to keep the base metal from corroding and increasing surface conductivity. Cadmium plating is also used as a sacrificial coating between stainless steel and aluminum to keep a galvanic reaction from occurring.
Cadmium metal is considered a toxic metal by the US EPA and many countries overseas. Therefore many items which were once cadmium plated are now protected by other metals. Because of the properties of cadmium no single cost effective alternative has been found for every application as a replacement. Using cadmium in many applications can be justified by comparing the effects on the environment with cadmium substitutes.
Typical thicknesses for cadmium plating are 0.0002″ to 0.0005″. Clear, yellow and olive drab chromates are available post treatments and the corrosion resistance increases with the darkness of the chromate without the part getting powdery.
Frequently Asked Questions:
Q: Can zinc plating take the place of cadmium plating?
A: Not in every situation. Cadmium has 2 to 3 times the corrosion resistance of zinc. Zinc does not have the lubricity, conductivity, or solderability of cadmium.
Chemical Film/Alodine
Alodine 1200S, Iridite 14-2, Iridite NCP
MIL-C-5541 all Types & Classes and AMS 2473
Chemical Film or Chromate Conversion Coating on Aluminum is a surface treatment which enhances the corrosion resistance of aluminum. Although it appears to be one of the simpler processes, it seems to have the most names and specifications. In addition to maximize the corrosion resistance of chemical film, certain pretreatment and post treatment steps are of the utmost importance. Chemical films are used for corrosion resistance and a paint base. When electrical conductivity and corrosion resistance are both required, chemical film is a good choice.
The coating comes in both iridescent yellow and clear colors; however, it should be noted that the yellow gives superior corrosion resistance. The lighter color gives lower electrical resistance. It should also be noted that chemical film is fragile directly after processing and a 24 hour waiting time before handling the parts is preferable. Temperatures over 120 F will also break down the corrosion resistance of the coating. In comparison to anodizing, the chemical film is fragile and it is not fit for high use areas as the coating can be easily damaged.
The old chemical formulations all contained hexavalent chrome which is not RoHS compliant (Type I of the MIL spec.) The new chemical formulations are RoHS compliant and they do not dye the surface of the metal a color. For Type II MIL spec coatings and RoHS compliance, we have a trivalent chromium formulation (Alodine T5900) and a non-chromium formulation (Iridite NCP) available which is RoHS compliant.
Frequently Asked Questions:
Q: Does chemical film add thickness?
A: No, chemical film is a surface treatment and it will not build up. It should be noted that some companies will heavily etch the surface for cleaning before processing. If you have close tolerances, please let the operator know so he will not etch off too much material.
Names for Chemical Film:
Generic Names:
- Chemical Film
- Chemical Conversion Coating of Aluminum
- Chromate Conversion Coating of Aluminum
- Passivation of Aluminum
- Yellow Chromate
- Clear Chromate
Proprietary Names:
- Alodine ~ Trade name of Henkel Technologies
- Iridite ~ Trade name of MacDermid
Chrome Plating – Decorative
Polished – Satin/Brushed
Sorry – No car parts.
Decorative chrome plating is an electro-chemical process which deposits a thin layer of chrome over a deposit of bright nickel plating. The bright nickel plating is usually about 0.0005″ thick and the chrome is typically 0.00004″ to 0.0001″ thick. The bright nickel has the great shine which we all love to see. The chrome is applied to keep the nickel from tarnishing and gives that crisp blue tint to the shiny “silver” color. It should be noted that all the scratches and blemishes must be removed from the base metal before plating to get that smooth, slick finish.
The chrome can also be applied as a dull, brushed, or satin finish such as on a firearms or medical equipment. The dull finishes reduce reflection and give a surface which will hide blemishes.
Sometimes you will notice yellow-brownish marks on decorative chrome parts. This is the nickel undercoating showing. I was in the grocery store the other day and I noticed that all the chrome was worn off the top of the shiny bar which separated the cash registers. You could see the yellow-brownish tint as opposed to the blueish tint of chrome.
Chrome Plating – Industrial Hard
Large and Small Items
QQ-C-320 and AMS2406
Industrial or hard chrome plating is the electro-chemical process of depositing chrome directly on the base metal of the part. It is used primarily for wear resistance and it does give a limited amount of corrosion protection. The most common example of hard chrome plating would be hydraulic cylinders. Many other mechanical parts are also hard chrome plated for wear resistance.
Hard chrome can be deposited on steel, stainless steel, high nickel alloys, and copper alloys. Although it is possible to plate chrome directly on aluminum, only a few companies are capable of doing this. Quality Plating Co. is not capable of hard chrome directly on aluminum.
The coating thickness varies from 0.000050″ to 0.050″. As all electroplating the coating thickness will vary according to the geometry of the part being plated. Points, edges and the top & bottom of the part will build up more chrome than the recessed areas, insides of corners and center of parts. The uneven buildup becomes more prevalent as the coating thickness increases. For this reason many parts are ground after plating to bring the part to size.
Copper Plating
Polished – Antique – Satin/Brushed – Industrial
Mil-C-14550 Class 0,1,2,3 & 4
Copper plating is an electro-chemical process which deposits a thin layer of copper on metals. Copper is used as an undercoating, a maskant for case hardening, and a decorative finish. The typical plating thickness is 0.000020″ to 0.002″.
Copper is used as an undercoating to assist with adhesion to the basis metal. It is commonly used before nickel plating.
Copper is used as a maskant for carburizing. The thickness of the copper is typically 0.002″ thick for this purpose and it must be plated from an alkaline bath.
Copper is plated over nickel as a decorative finish. It can have a polished, satin or antique finish. The finished piece is then lacquered so the copper will not tarnish.
Decorative Finishes
Lacquering included on all finishes except chrome.
- Brass ~ Polished – Antique – Satin
- Chrome ~ Polished – Satin – Brushed
- Copper ~ Polished – Antique – Satin
- Nickel ~ Polished – Antique – Satin – Pewter
- Gold ~ Polished – Satin
- Silver ~ Polished – Satin
- Oil Rubbed Bronze
- Black and Dull Black finishes
These Gold and Satin Nickel Plated chandeliers hanging in Grand Central Station in New York City were re-plated at our plant in Salt Lake City.
Dow #7
Mil-M-3171 Type I and III
Dow #7 is a chromate conversion coating on magnesium. It forms a protective layer to help prevent corrosion and it also works well as a paint base on magnesium. It is similar to a chemical film on aluminum.
Gold Plating
24K available
MIL-G-45204, AMS 2422 and ASTM B488
Gold plating is the electro-chemical process of depositing a thin layer of gold on metal. Gold can be plated directly on a base metal or it can be applied over an undercoating such as nickel to improve adhesion of the gold itself. The purpose for gold plating includes conductivity, decoration, corrosion protection and reflectivity. We are experienced in plating electrical contacts, decorative artworks, satellite and aircraft parts.
Gold is often used for conductivity instead of silver because it is a cleaner tarnish free surface. Gold is also impervious to certain chemicals making it the preferred choice with respect to corrosion protection under special applications.
Gold is plated in thicknesses starting at 0.000007″ which is used for costume jewelry. Our thickness limit is 0.0001″. 0.00002″-0.00003″ is a commonly used thickness for some wear. Our gold is alloyed with cobalt and nickel and they are considered a hard gold.
In most plating processes, materials are a small part of the cost, but with gold the material cost becomes a determining factor especially on parts with large surface areas.
The gold stars on the Wall of Stars as part of the World War II Memorial in Washington DC were plated at Quality Plating Co., Inc. When the first stars were received, the stars were beat up and dull. Having expected bright polished stars, I immediately called our customer about the mistake. I discovered that the artist felt the United States came out of the war battered and worn, and he wanted the stars to represent that image. I believe the United States came out of the war as a shining star of freedom and I still feel the stars should have been a polished gold finish – but who am I.
Nickel Plating
Polished – Satin – Antique (Pewter Finish)
QQ-N-290 Class 1 & 2 Grade A through G; AMS 2403
Nickel plating is the backbone of decorative electroplating. Nickel has properties which allow it to shine, throw into corners and even smooth out surfaces. It is the undercoating for most shiny plating surfaces.
Nickel itself has a very nice color. The chrome can sometimes look cold with its blue tint; but nickel has a warmer, yellow-brownish tone. It is a common finish on coal stoves, and antique items.
Nickel Plating – Electroless
Mil-C-26074 all Classes & Grades, AMS 2404 and ASTM B733
Electroless nickel is a plating process which deposits an even layer of a nickel-phosphorous alloy on a part. It’s properties include corrosion resistance, hardness, and abrasion resistance. A typical thickness of plating varies from 0.000050″ to 0.002″ thick. The beauty of this process as compared to electrolytic processes is that the coating builds up evenly on all surfaces the solution touches with adequate circulation.
Our process deposits approximately a 93% nickel/7% phosphorous coating which is considered a “mid-range” alloy. Other processes with less phosphorous produce coatings with less corrosion resistance and more hardness. Processes with more phosphorous produce coatings with more corrosion resistance and less hardness.
Our electroless nickel deposit as plated has a hardness of about Rc 45 and it can be baked to produce a hardness between Rc 50 and 55.
Electroless nickel is used on molds, machine parts, valves, aircraft . . . We can plate it on aluminum alloys, nickel alloys, steel alloys and copper alloys.
Nickel Plating – Sulfamate
QQ-N-290 and AMS 2424
Sulfamate nickel plating, also called ductile nickel, is an electro-chemical process which deposits a thin layer of nickel on a metal base. It is used primarily for functional purposes like corrosion protection and salvaging parts. It can be applied in thicknesses from 0.00005″ to 0.050″.
Sulfamate nickel is soft enough to machine. Because it can be built up heavy, it is used to salvage undersize parts when a hard surface is not required. It is also used for corrosion protection of parts which stretch or move because the soft nickel is ductile and will bend without cracking.
It should be noted that the coating thickness is not uniform on all surfaces. As is usual in electroplating the high current density areas (edges, points, top or bottom) builds up faster than the low current density areas (recessed areas, inside corners, center of plates.) This becomes more evident as the thickness of the coating increases.
Passivation of Stainless Steel
QQ-P-35 Type II, VI, and VII, Mil-S-5002, ASTM A380, ASTM A967, AMS 2700
Passivation of Stainless Steel is a process which treats the surface of the metal to impede corrosion. The process has two primary functions: first, to remove any free iron on the surface of the material and second to promote the growth of nickel and chrome oxides which give stainless steel its excellent corrosion resistant properties.
Passivation does not removed discoloration or heat scale from the surface of the part. An additional acid pickle, an alkaline descaler or mechanical blasting are required to remove such material from the surface.
Passivation is used in many industries and a broad sprectrum of stainless steel and nickel alloys can be passivated. These include 300 series, 400 series, Inconel, Hastelloy, 17-4, 13-8 and A286. It should be noted that if a stainless steel is improperly heat treated there is a risk of etching the parts in the passivation process – this mostly a concern for 400 series alloys.
Phosphate – Manganese
DOD-P-16232 Type M
Manganese phosphate is used to improve the corrosion resistance and the lubricity of steel. It is typically oiled or sprayed with a dry film lubricant. It is a somewhat grainy surface which is best applied on a sandblasted surface. The grain is much more even on a sandblasted surface.
The amount of phosphate applied is typically specified by coating weight and not thickness. This is because the coating is soft and grainy and it can be difficult to know when to stop turning the micrometer. A heavy manganese coating can add several thousandths of an inch to each surface.
Phosphate – Zinc
DOD-P-16232 Type Z; TT-C-490 Type V
Zinc phosphate coating is an immersion process which forms a grainy phosphate coating on steel. It is often called “Parkerizing.” Zinc phosphate is used for corrosion resistance or a paint base and the items are either oiled or painted after processing. The zinc phosphate acts as a sacrificial coating for steel.
Polishing
Aluminum or Steel
Sanding
Silver Plating
QQ-S-365 and AMS 2412
Silver plating is an electro-chemical process which puts a thin layer of silver over another metal. It is principally used for lubricity, conductivity and decoration. It is used on products like gears and seals for lubricity, buss bars and contacts for conductivity and pieces of art for decoration. We are very successful in plating silver for each of these purposes. A typical thickness for silver plating is 0.0001″ to 0.0005″.
When silver is applied for lubricity and conductivity, it is typically plated directly on the base metal, unless an undercoating is required for adhesion such as a nickel strike to help the plating adhere to nickel alloys. For decorative applications the silver may have an undercoating of bright nickel to take advantage of the nickel’s ability to shine.
Frequently Asked Questions:
Q: Why is silver used for electrical connections even though it tarnishes so fast?
A: Tarnished silver or silver oxide is almost as conductive as silver and it is still more conductive than gold.
Tin Plating
Mil-T-10727 Type I, ASTM B545
Tin plating is an electroplating process which deposits a thin layer of tin on a metal surface. Tin is most commonly plated directly on the base material without an undercoating. It’s most common uses are corrosion protection and solderability. It is used on copper buss bar to protect the buss bar, as well as help the solderability of the copper. Tin plating can be used on items which can be found around food; however, mixing bowls, pots and other kitchen devices are more commonly “hot-dipped” in molten tin.
Zinc Plating
Parts up to 116 inches long
ASTM B633 All types and classes
Zinc plating is a process which deposits a thin layer of zinc over a metal substrate which is usually steel. It is different from galvanizing because zinc plating is an electro-chemical process and not a dip in molten zinc like galvanizing. The advantages of zinc plating over galvanizing are control over zinc thicknesses, smoother surfaces and less damaging to fragile parts. The disadvantage is less corrosion resistance since the zinc thickness is much thinner. Zinc plating has also been called electrogalvanizing.
Zinc plating is commonly used on fasteners and sheet metal fabricated parts in thickness from 0.0001″ to 0.0005″ thick. It should be noted that since zinc plating is an electroplating process thickness will vary with locations on the part and inside areas will not be plated without special considerations.
Zinc plating protects the steel as a sacrificial coating as well as a barrier like nickel plating. The advantage of a sacrificial coating is if the coating is damaged, the rust has a more difficult time penetrating the material around the damaged coating. Zinc plating is also a good paint base and it will greatly improve the corrosion resistance of the paint.
The actual zinc plating is RoHS compliant; however, the chromates which are applied to the zinc plating to increase the corrosion resistance are not necessarily RoHS complaint. At this time our clear chromate, Type III, is RoHS compliant. We still offer a yellow chromate, Type II, which does not meet RoHS compliance. We do offer a heavy build chromate with is a greenish-blue color which will meet the salt spray requirements of a traditional yellow chromate and it offers RoHS compliance.