Coating and Plating Specifications

Coating and Plating Specifications

PROCESS	METAL	APPLICABLE SPECIFICATION	NORMAL COATING THICKNESS AND COLOR OR APPEARANCE	REMARKS
ALODINE		See CHEMICAL FILMS
ANODIZE - CHROMIC ACID	ALUMINUM	MIL-A-8625 TYPE I - Conventional TYPE IB - Low Voltage CLASS 1 - Non Dyed CLASS 2 - Dyed	0.00002 -0.0003 Clear to dark gray depending on alloy.	Not to be applied with copper content in excess of 50% silicon in excess 7.0% and when total alloying elements exceed 7.5% Non-conductive, good paint base, poor abrasion resistance, not good for dyes except black, should be used.
ANODIZE - SULFURIC ACID	ALUMINUM	MIL-A-8625 TYPE II CLASS 1 - Non Dyed CLASS 2 - Dyed	0.00007-0.001 Clear All Colors	Not to be applied to assemblies or part with joints or recesses which might entrap solution. Good electrical barrier and paint base. May be dyed in all colors. Dichromate seal will impart yellow color. Produces excellent decorative finishes when the part is either polished, brushed, or bright dipped prior to anodizing. Good abrasion resistance.
ANODIZE - HARD (includes Martin and Surge Hardcoat)	ALUMINUM	MIL-A-8625 TYPE III CLASS 1 - Non Dyed CLASS 2 - Dyed	Unless otherwise specified, 0.0016/0.0024 will be applied. Color will vary alloy and thickness.	Dense hard wear resistant coating. Coatings are approximately 50% penetration and 50% buildup. Excellent dielectric and heat absorption properties. Should be considered for salvage applications. Sealing greatly increases corrosion resistance, but slightly reduces wearing qualities. Teflon sealing may be added to increase lubricity.
ANODIZE - DURASEAL	ALUMINUM	NONE	No Dimensional change All colors	The ultimate seal for corrosion resistance on alloys. We have independent salt spray tests that have withstood 1,000+ hours without pitting on 6061 and 2024 aluminum alloys.
ANODIZE - ARCHITECTURAL (Kalcolor process: also called Bronze Anodize)	5052-H34 & 6063-T6 ALUMINUM ALLOYS	Aluminum Association Standard AA-A42 - CLASS I AA-A3A - CLASS II ASTM B580	CLASS I - 0.0007 minimum CLASS II - 0.0004 - 0.0007 Light to dark bronze.	Integral-color (non-dyed) hardcoat. Excellent corrosion and abrasion resistance. Non-dyed integral-color is lightfast and depends on alloy used. CLASS I is recommended for exterior applications and CLASS II for interior applications.
ANODIZE PRINTING	ALUMINUM	NONE	0.0001-0.0004 Clear All colors	A method of anodizing letters, symbols, characters, logos, and numerals on an anodized background. The letters are of one color and the background of another. Superior to regular ink printing because of the corrosion and solvent resistance of anodize, and is an excellent alternative to engraving.
BAKING	ALL	In accordance with applicable plating specification	No dimensional change Slight staining may result	Used for hydrogen embrittlement or stress relief before and/or after processing, for improving the adhesion of plating the base metal, and increasing the hardness of plating.
BLACK OXIDE	IRON, STEEL, STAINLESS STEEL, COPPER, ALLOYS	MIL-C-13924 CLASS 1 - Iron & Steel CLASS 2 - 400 series stainless steel CLASS 3 - Fused salt process CLASS 4 - Stainless steel MIL-F-495	No dimensional change Black	Poor abrasion resistance. Poor corrosion resistance except for some 300 series stainless steels with CLASS 4 coating. Used where a black surface and low light reflection is required. Supplementary wax or oil dip (VV-L-800 Preservative Water Displacing Oil) Will improve appearance and corrosion resistance. Good for decorative purposes when base metal is polished before processing protection is included.
BLASTING (includes glass bead and powder blasting)	ALL	MIL-STD-1504	Removes metal Dull to semi-bright	For removing scale and rust, etc., and blending imperfections. The amount of metal removed will depend on media selected. May be used for decorative and optical finishes. Provides uniform matte finish before decorative processing.
BRASS	ALL	NONE	.0002-.0005 Dull to bright	Normally preceded by bright nickel plate and pst treated with a coat of clear lacquer or baked enamel.
BRIGHT DIPS	ALUMINUM, BRASS, COPPER	NONE	Removes metal Bright	Chemical polishing which improves appearance of finishes on aluminum, bass and copper. Used for cleaning metal before welding and pressure testing
CADMIUM	ALL	QQ-P-416 TYPE I - Without supplementary chromate treatment TYPE II - With supplementary chromate treatment TYPE III - With supplementary phosphate treatment	CLASS 1 - 0.0005 CLASS 2 - 0.0003 CLASS 3 - 0.0002 TYPE I - Clear TYPE II - Gold TYPE II - Gray Dull to bright	Most commonly used plating. High density of plate affords excellent corrosion resistance. TYPE I coating is very susceptible to stains and fingerprints. TYPE II coating is excellent for resistance to moisture and humidity, and a paint base. Chromate colors besides gold are clear, black, and olive drab. TYPE III is a good paint base. Stress relief is required on metal with a hardness of Rockwell C34 or above before plating and hydrogen embrittlement relief is required on metal with a hardness of Rockwell C36 or above after plating.
CHEMICAL FILMS (Alodine, Iridite, etc.)	ALUMINUM	MIL-C-5541 CLASS 1A for maximum protection against corrosion on painted or unpainted surfaces CLASS 3 for protection against corrosion where low electrical resistance is required.	No dimensional change Gold or clear as specified.	Used mainly as a point base that improves paint adhesion. Good corrosion resistance. Electrically conductive. Normally gold color unless otherwise specified. CLASS 3 coating is used primarily for low electrical resistance contact and has less corrosion resistance that CLASS 1A coating.
CHROMIUM	ALL	QQ-C-320 CLASS 1 - Corrosion protective (decorative) TYPE I - Bright TYPE II - Satin CLASS 2 - Engineering (hard)	CLASS 1 - 0.0001 - 0.00005 (plus underplate) CLASS 2 - 0.002 unless otherwise specified Dull to bright	Decorative chrome is normally applied over copper and nickel plate. TYPE I bright coating is put on either the base metal that is polished or as is. TYPE II satin coating is put on the base metal that is either blasted, grained or brushed. Hard chrome is plated directly on the base metal. Parts requiring heavy metal deposits should be overplated and ground to the final finished dimension.
CHROME PICKLE		See DOW #1
CHROMIC ACID TOUCH UP		See DOW #19
COPPER	ALL	MIL-C-14550	CLASS 0 - 0.001 - 0.005 CLASS 1 - 0.001 min. CLASS 2 - 0.0005 min. CLASS 3 - 0.0002 min. CLASS 4 - 0.0001 min.	Stop off for heat treat (CLASS 0) and carburizing (CLASS 1). Undercoat for other plated metals to improve adhesion, corrosion resistance, and to increase electrical conductivity (CLASS 2). Under tin plating to prevent base metal migration into the tin to poison solderability (CLASS 3 and CLASS 4)
COPPER SULFATE TEST		See Testing
DICHROMATE		See DOW #7
DOW #1 (Chrome Pickle)	MAGNESIUM	MIL-M-3171 TYPE I	Removes 0.0006 - 0.001 metal Gray to brown	For temporary corrosion resistance. Affords such protection as may be required during machining, shipment, and storage. My be used as a paint base.
DOW #7 (Dichromate Treatment)	MAGNESIUM	MIL-M-3171 TYPE III	No dimension change Brassy to dark rown	Good paint base. Best corrosion protection of the chemical coatings for magnesium. May be applied to all alloys except EK30A, EK+1A, EZ33A, HK31A, M1A, HM31A, HM21A, and LA141A.
DOW #9 (Galvanic Anodize)	MAGNESIUM	MIL-M-3171 TYPE IV	No dimension change Dark brown to black	Good paint base. Used on alloys that won't take DOW #7 and parts requiring a non-reflective black coating.
DOW #17 (Anodize)	MAGNESIUM	MIL-M-45202 TYPE I - Light Coating CLASS C - Light green coating TYPE II - Heavy Coating CLASS D - Dark green coating	TYPE I CLASS C 0.0001 - 0.0005 Light Green TYPE II CLASS D 0.0009 - 0.0016 Dark Green	Machining allowances must be made. Good paint base and corrosion protection. Hard non-conductive coating. Castings should be picked, prior to machining, to remove scale and insure uniformity of the coating. The coating thickness is approximately 40% penetration and 60% buildup.
DOW #19 (Chromic Acid Touch Up)	MAGNESIUM	MIL-M-3171 TYPE VI	No dimensional change Brassy to Brown	Commonly used to touch up rack marks, surface scratches, reworked areas, and surfaces that have been remachined or abraded.
DOW # 21 (Ferric Nitrate Bright Pickle)	MAGNESIUM	NONE	Removes metal Satin to Bright	Good paint base. Poor corrosion resistance. May be coated with laquer or clear bake enamel to preserve brightness.
DOW #23 (Stannate Immersion)	MAGNESIUM	NONE	Under 0.0001 Gray	Layer of tin that retards galvanic corrosion from dissimilar metals. Good paint base and has low electrical resistance.
DRY FILM LUBRCATION or DRY LUBE		See SOLID FILM LUBRICANT
ELECTROLESS NICKEL	ALL	AMS 2404 CLASS 1 - As plated, no subsequent heat treatment CLASS 2 - Heat treated to obtain required hardness CLASS 3 - On aluminum alloys, nonheat-treatable, & beryllium alloys, processed to verify nickel adhesion CLASS 4 - On aluminum alloys, heat-treatable, processed to verify nickel adhesion	THICKNESS AS SPECIFIED Semi-bright	100% uniformity of plating thickness on all accessible internal and external areas. Exceptionally good for salvage purposes. Good corrosion, oxidation, and wear resistance. Facilitates soldering on aluminum and brazing on stainless steel. CLASS 1 and CLASS2 coated steel parts. Rockwell C33 or above, are baked for hydrogen embrittlement relife. CLASS 2 coated parts are additionally heated to 450 degrees F. or more, to harden the nickel deposit. This heat treatment should increase the plating hardness to 800 Knoop or better, for CLASS 2 coatings.
ETCHING	MOST	NONE	Removes metal. Dull to bright	To improve appearance, remove burrs and oxidation, clean for spot welding, give satin finish, etc.
GALVANIC ANODIZE		See DOW #9
GOLD	ALL	MIL-G-45204 TYPE I - 99.7% gold min GRADES A, B, OR C TYPE II - 99.0% gold min. GRADES B, C, OR D TYPE III - 99.9% gold min. GRADE A (only)	CLASS 00 - .00002 min CLASS 0 - .00003 min CLASS 1 - .00005 min CLASS 2 - .0001 min CLASS 3 - .0002 min CLASS 4 - .0003 min CLASS 5 - .0005 min CLASS 6 - .0015 min Dull to bright	GRADE A - Knoop hardness 90 max. GRADE B - Knoop hardness 91-129. GRADE C - Knoop hardness 130-200. GRADE D - Knoop hardness 201 and over. Good solderability, corrosion, and tarnish resistance. When plated on a copper rich surface such as brass, bronze, beryllium copper, copper strike or plate, a nickel underplate is applied to prevent diffusion of the copper and the gold. Coating thickness of .00005 - .0001 is best for soldering.
HAE (A superior type of anodic coating)	MAGNESIUM	MIL-M-45202 TYPE I - Light coating CLASS A - Tan coating GRADE 1 - No post treatment GRADE 2 - With bifluoride dichromate post treatment TYPE II - Heavy coating CLASS A - Hard brown coating GRADE 1 - No post treatment GRADE 3 - With bifluoride- dichromate post treatment GRADE 4 - With bifluoride- dichromate post treatment including moist heat aging GRADE 5 - Same as GRADE except double bifluoride-dichromate post treatment	TYPE I CLASS A 0.0001 - 0.0003 Tan TYPE II CLASS A 0.0013 - 0.0017 Oatmeal to dark brown	It is generally agreed by most authorities that this treatment is the best all around coating for magnesium in existence. The coating thickness is approximately 35 to 40 percent penetration and 55 to 60 percent buildup. When selected organic post-treatments are applied, a salt spray test of up to 1000 hours is possible. The coating is non-conductive. TYPE II coatings have extremely good resistance to abrasion. TYPE I light coatings are normally tan in color. TYPE II heving coatings will range from an oatmeal color to dark brown, depending on the thikness of the coating. HAE coatings are not affected by extream tempurature variations. A heavy coated panel heated to 1075 degrees F. and plunged into ice water will show no ill effects to the coating. This process can be selectively applied by masking the areas that have to be free of coating for: electrical grounding, close tolerance dimensions, heavy buildups for salvage purposes, etc. The coating may be used on all magnesium alloys.
HARDNESS/ CONDUCTIVITY TESTING	ALL	ASTM E18 MIl-STD-1537	No dimension change No appearance change	Hardness testing is used to check the temper or condition of materials. The results are expressed in the Rockwell superficial bardness of metallic materials. Hardness values for nonferrous alloys do not give absolute correlation with mechanical properties, as with ferrous alloys. Hardness testing on nonferrous alloys should be used to detect incorrect heat treating or damage caused by maching. Conductivity testing uses electromagnetic introduction to test physical properties such as hardening, anneling, changes in alloy composition, heat treating, and aging, etc.
HUMIDITY TEST		See TESTING
HYDROGEN EMBRITTLEMENT RELIEF		See BAKING
IRIDITE		See CHEMICAL FILMS
IRIDITE #15	MAGNESIUM	MIL-M-3171 TYPE VIII	Experience shows it may remove metal Brassy to dark brown	Good paint base on all alloys. Limited corrosion protection. Used for alloys that won't take Dow #7. Careful control is necessary to avoid etching of base metal.
MAGNETIC PARTICLE INSPECTION	STEEL AND MAGNESIUM MATERIALS	ASTM E14444	No dimensional change No appearance change	This inspection method is used for detecting cracks, seams, laps, inclusions, welding flaws, and dicontinuities on the surfaces of ferromagnetic materials.
NICKEL (Electrodeposited)	ALL	QQ-N-290 CLASS 1 - Corrosion protective CLASS 2 - Engineering (Also see SULFAMATE NICKEL)	CLASS 1 GRADE A - .0016 GRADE B - .0012 GRADE C - .0010 GRADE D - .0008 GRADE E - .0006 GRADE F - .0004 GRADE G - .0002 CLASS 2 - as specified	There is a nickel finish for almost any need. Nickel can be deposited in soft or hard form, dull or bright finish. Corrosion resistance is related to the thinkness applied. Low thermal expansion. Slightly magnetic. CLASS 2 plating will be .002 to .003 thick unless otherwise specified, but may be controlled to fit any engineering application. CLASS 1 coatings that include copper undercoat are used for decorative chromium systems. Embrittlement relief is required on all metals with hardnesses above Rockwell C40.
PAINTING (Spray)	All	MIL-T-704 MIL-F-7179 MIL-F-18264	Thickness as specified Colors per FED-STD-595 or custom matched	Our facilities can apply matherials such as alkyd, acrylic, epoxy, and polyurethane enamels; vinyl and acrylic lacquers; varnishes and resin coatings; epoxy, acid-wash, red oxide, and zinc chromate primers. Finishes such as class A, hammertone, wrinkle, and texture. Also, see SOLID FILM LUBRICANT.
PASSIVATE	STAINLESS STEELS	QQ-P-35 TYPE II - Medium temperature nitric acid solution with sodium dichromate additive TYPE VI - Low temp. nitric acid solution TYPE VII - Medium Temp. nitric acid solution TYPE VIII - Medium temp. high concentration nitric acid solution	No dimensional change No appearance change	Dissolves all traces of foreign metals such as peices of iron particles, tool scrapings, chips, etc., that will cause rust or stain spots if they are not removed. A thin, transparent passive film forms over the surface and prevents this condition from occurring. The presence of rust and/or heavy heat treat scale may necessitate a pre-pickle. For the 400 and precipitation hardening series of stainless steels, the proper heat treatment is very important to ensure complete passivation. Our inspection personnel conduct the required copper sulfate, salt spray, and water immersion inspection tests in our own testing department and chemical laboratory in accordance with MIL-STD-753 and ASTM B117. (see TESTING).
PENETRANT INSPECTION	ALL	MIL-STD-6866 TYPE I - Fluorescent dye TYPE II - Visible dye METHOD A - Water washable METHOD B - Post emulsifiable (lipophilic) METHOD C - Solvent removable METHOD D - Post emulsifiable (hydrophilic)	.0002-.0004 metal removal on aluminum and magnesium alloys No dimensional change on other types of metals No appearance change	This process is generally used on aluminum, magnesium, and stainless steels. It can, however, be useful on other metals and materials. Detects cracks, discontiuities, corrosion, welding flaws, laps, cold shuts and porosity. Prepenetrant etching is performed on aluminum and magnesium parts. Critical surface finishes and areas with close tolerances are masked, as required, to protect them from metal removal, prior to the etching operation.
PHOSPHATE (Heavy)	IRON AND STEEL	DOD-P-16232 TYPE Z- Zinc base CLASS 1 - Specified treatment of supplementary preservative CLASS 2 - MIL-C-16173 GRADE 1 preservative treatment CLASS 3 - No supplementary preservative treatment CLASS 4 - Chemically converted	.0002-.0006 1022 mg/sq ft minimum coating weight Gray	Used for corrosion protections of ferrous metals. Also used to prevent galling in cold extrusion and deep-drawing applications. Not recommended if the coating is expected to come in contact with alkaline materials or to be exposed to temperatures above 200 degrees F. CLASS 2 and CLASS 4 coatings extend the corrosion protection of the phosphate. MIL-L-3150 oil may be used as an alternative for very small parts under CLASS 2. CLASS 4 provides an improved break-in coating.
PHOSPHATE (Light)	IRON AND STEEL	TT-C-490 Zinc base TYPE I TYPE V	Minor dimensional change 150-500 mg/sq ft coating weight 500-1100 mg/sq ft coating weight. Gray	Used for pretreatment of base metal for organic coatings such as primer enamel, lacquer, etc. Improves corrosion resistance of the base metal, and promotes better adhesion between the base metal and the organic coating. Also, use for post treatment of both cadmium and zinc plating.
PICKLING	ALL	In accordance with applicable plating specifications	Removes metal Cleaner and brighter surface	Generally used as a cleaner to remove corrosion, rust, and scale from heat treating or weling. The hazards involved in this process should be investigated before using.
POLISHING	ALL	NONE	Removes metal Satin to bright	Bright buffing and satin brushing, or graining for plated or unplated decorative finishes. Removes surface imperfections.
PREVENTIVE COMPOUND SOLVENT CUTBACK COLD- APPLICATION	ALL	MIL-C-16173 GRADE 1 - Hard film GRADE 3 - Soft film GRADE 4 - Transparent, non- tacky film GRADE 5 - Hot water-low pressure removable film	GRADE 1 - .004 max. (0 to 175 degrees F. resistant) GRADE 2 - .002 max. (-40 degrees F. resistant) GRADE 3 - .001 maximum GRADE 4 - .002 max. (-40 to 175 degrees F. resistant) GRADE 5- .001 maximum Brown to black	Corrosion preventives are applied in a petroleum solvent. The solvent evaporates leaving a protective film. GRADE 1 is for metals exposed to outdoor weather, for up to one year. GRADE 2 is for machine parts, indoors for up to six months. GRADE 3 is for displacing water and protection of interior parts for up to four months. GRADE 4 is for indoor or shed storage of parts. Also, where a tack-free or translucent coating is required. GRADE 5 is the same as GRADE 3 except the film is removed with hot water or low pressure steam.
SALT SPRAY TEST		See TESTING
SANDBLASTING		See BLASTING
SILK SCREEN PRINTING	ALL	AS SPECIFIED (Also see ANODIZE PRINTING)	No dimensional change All colors	An excellent means to label parts for identification and information with enamel, epoxy, lacquer, plastisol or vinyl inks. Print on metal anodized, bare, painted, plated, etc.
SILVER	ALL	QQ-S-365 TYPE I - Matte TYPE II - Semi-bright TYPE III - Bright GRADE A - With supplementary tarnish-resistant treatment GRADE B- Without supplementary tarnish-resistant treatment	.0005 unless otherwise specified. Suggested are: .0003 for soldering parts; .0005 for corrosion protection of nonferrous basis metals and increasing conductivity of basis metals .005 minimum - See REMARKS	Excellent conductivity. Application of light water dip lacquer or chromate treatment per GRADE A does not impair solderability. Greatly increases conductivity of lesser metals. Ferrous surfaces require and undercoat of .0005 comprised of copper or nickel or any combination. Nickel undercoat is advantageous when corrosion protection is important. .005 minimum thick coating is suggested for electrical contacts depending on pressure, friction, and electrical load.
SOLID FILM LUBRICANT	ALL	MIL-L-46010 TYPE I & TYPE II MIL-L-23398 MIL-L-45983 MIL-L-81329 MIL-L-85614	.0002-.0005 Dull gray to black	Pretreatment compatible with base material is normally necessary (anodize, chemical film, cadmium plate, blasting if required, etc.). Low co-efficient of friction reduces wear, prevents galling and seizing. Excellent fluid and corrosion resistance when used in conjunction with pretreatment.
STRESS RELIEF		See BAKING
SULFAMATE NICKEL	ALL	QQ-N-290 CLASS 2	.002-.003 or as specified Semi-bright	Low stressed nickel deposit. Used for wear and abrasion resistance. Also, for heavy buildups on worn parts and for salvage purposes.
TESTING	ALL PLATED AND UNPLATED	ASTM B117 - Salt spray MIL-STD-753 METHOD 100 - Humidity METHOD 101 - Water immersion METHOD 102 - Copper sulfate	No dimensional change No appearance change	These tests are designed to verify the integrity of various metals and metal surface finishes. The salt spray method is used extensively for testing of anodize, chemical films, and plated metal coatings. The salt spray, humidity, water immersion, and copper sulfate methods are used to check on the passivity of stainless steel after the passivation process.
TIN	ALL	MIL-T-10727 TYPE I - Electrodeposited TYPE II - Hot-dipped	TYPE I - Thickness not specified, suggested are: .0001-.00025 for soldering .0002-.0004 to prevent galling or seizing .003 minimum to prevent corrosion of base metal .0002-.0006 to prevent case forming in nitriding TYPE II - .0007 minimum Dull gray to bright silver.	Dull (matte) or bright appearance must be specified. Underplate of copper or nickel must be used on brass and zinc alloys. Excellent solderability and fair corrosion resistance. At room temperature TYPE I dull plating oxidizes or slowly but bright plating oxidizes less readily. Parts to be soldered or used for electrical contacts can be protected from oxide formation by a preservative coating of stearic acid as specified. TYPE I plating may be fused but thickness will vary after treatment. A maximum of .0003 thick plating must be maintained to permit satisfactory fusing. TYPE II hot-dipped coating is used on parts for maximum corrosion resistance.
WATER IMMERSION TEST		See TESTING
ZINC	ALL	ASTM B633 TYPE I - Without supplementary treatment TYPE II - With colored chromate conversion coatings TYPE III - With colorless chromate conversion coatings TYPE IV - With phosphate conversion coatings	Fe/Zn 25 (25 microns)-.001 SC 4 (very severe) Fe/Zn 13 (13 microns)-.0005 SC 3 (severe) Fe/Zn 8 (8 microns)-.0003 SC 2 (moderate) Fe/Zn 5 (5 microns)-.0002 SC 1 (mild) TYPE I - Clear TYPE II - Gold TYPE III - Clear TYPE IV - Gray Dull to bright	Gives galvanic protection to base metal. Untreated (TYPE I) zinc plating does not maintain its bright surface for a very long period of time. TYPE II and III treatments retard the formation of white corrosion products on the plated surface. The service life of zinc plating is a function of conditions such as thickness, exposure, and usage. The Service Conditions are as follows: SC 4 - Very Severe: Exposure to harsh conditions, or subject to frequent exposure to moisture, cleaners, and saline solutions, and damage by denting, scratching, or abrasive wear. SC 3 - Severe: Exposure to condensation, perspiration, infrequent wetting by rain, and cleaners. SC 2 - Moderate: Exposure mostly to dry indoor atmospheres but subject to occasional condensation, wear, or abrasion. SC 1 - Mild: Exposure to indoor atmospheres with rare condensation and subject to minimum wear or abrasion.