Military Plating Specifications
PROCESS MIL.SPEC THICKNESS COMMENTS
BLACK CHROME  MIL-C-14538 . .
    As specified on drawing Color is a dull gray, approaching black.
The Black Chrome surface may be waxed ot oiled to darken the surface.     It shall approximate color plate 37038 of Fed Std No. 595
BLACK OXIDE COATING  MIL-C-13924 . .
A uniform black coating for ferrous metals. Mostly a decorative coating. Only very limited corrosion protection under mild corrosion conditions.   No dimensional range For moving parts which cannot tolerate the dimensional change of a more corrosion resistant finish. For decorative applications and can be used to decrease light reflection.
  Class 1   Alkaline oxdizing. For wrought iron, cast and malleable irons, plain carbon and low alloy steels.
Black oxide coatings should normally be given a supplemental treatment (i.e. oil displacement per MIL-C-16173 Grade 3 or protection treatments of MIL-C-16173). Class 3   Fused salt oxidizing. For corrosion resistant steel alloys which are tempered at 900°F (482°C) or higher.
  Class 4   Alkaline oxidizing. For 300 series corrosion resistant steel alloys only.
CADMIUM  QQ-P-416 . .
Bright silvery white. Supplementary treatment for Type II can be golden, irdescent, amber, black, olive drab. Corrosion resistance is very good, especially with Type II finish. Type II shall show no surface corrosion products after 96 hours (5%) salt spray exposure. Partrs with hardness greater than 40-Rc shall be stressed relieved before cleaning and plating. Parts subject to flexure (springs, etc.) over Rc-40 hardness, shall be given a 375° +- 25°F post bake. Type I   No Supplementary treatment
Type II   Supplementary chromate treatment
Type III   Supplementary phosphate treatment
Salt-Spray Test      
Type II Class 1 Test Period for White Corrosion Products (Hours) 96 Hours Class 1 0005 min Type II best for corrosion resistance
Class 2 0003 min Type III is used as a paint base. Excellent for plating stainless steels that are to be used in conjuction with aluminium to prevent galvanic corrosion
Class 3 0002 min
CHEMICAL FILMS  MIL-C-5541 . .
Materials qualified produce coatings that range in color from clear to iridescent yellow or brown. Inspection difficulties may arise with clear coatings because visual inspection does not reveal the presence of a coating. Class 1A   Class 1A chemical conversion coatings are intended to provide corrosion prevention when left unpainted as well as to improve adhesionof paint finish systems on aluminum and aluminum alloys. May be used on tanks, tubings, and components structures where paint finishes are mot required for the exterior surfaces but are required for the interior surfaces.
Class 3   Class 3 chemical conversion coatings are intended for use as corrosion preventative film for electrical and electronic applications where lower resistant contacts, releative Class 1A coatings, and anodic coatings wil MIL-A-, are required. Th eprimary difference bewteen a Class 1A and Class 3 coating is thickness
CHEMICAL FINISH; BLACK  MIL-C-495 . .
A uniform black corrosion retardant for copper. Coating has no abrasion resistance.      
CHROME  QQ-C-320 . .
Excellent hardness (Rc 68-74), wear resistant and erosion resistance. Has low coefficient of friction, and is resistant to heat. In addition to above properties, can be rendered porous for lubrication purposes Type I   Bright.
Type II   Satin.
Class 1 00001 min on all visible surfaces Corrosion protection plating
Class 2 As specified on drawing. If thickness not specified, min thickness shall be 002 Engineering plating
Post bake at A89° for 3 hours or as specified Class 2a   Plated to Specified dimensions or processsed to Specified dimensions after plating
Shot peening and post baking not required Class 2b   Parts below Rockwell C40 and subject to static loads or designed for limited life under dynamic loads
Shot peen per MIL-S-13165 or MIL-R-8141 Class 2c   Parts below Rockwell C40 and subject to unlimited life under dynamic loads
Post bake at 375° +- 25° for 3 hours Class 2d   Parts have hardness of Rockwell C40 or above and subject to static loads or designed for limited life under dynamic loads.
Shot peen before plating. Post bake at 375° +- 25° for 3 hours Class 2e   Parts have hardness of Rockwell C40 or above and designed for unlimited life under dynamic loads.
CHROMIC ANODIZE MIL-A-8625 . .
Color will cary from light gray to dark gray depending on alloy. Not as readily died as sulfuric anodize. Type 1A .00002" - .00007" Conventional coating produced from chromic acid bath. Unless otherwise specified, coating wil be sealed. Metal salt sealants should not be used on items that will be painted.
New salt spray requirements is 336 hours (5% solution per method B-117 of ASTM) Type 1B Class 1   Low voltage chromimic acid anodizing 20V Non-dyed (Natural including dichromate seatings).
Minimum weight for Type I coatings: Class 1 200 Miligrams sq ft. Class 2 600 Milligrams sq ft. Because of thiness will scratch easily. Can be used for inspection of aluminum forgings or castings by noting evidence of chromic acid bleed out from taps, cracks, seams, etc. Class 2   Dyed Shall not be applied to alumium alloys with over 5.0% copper, 7% silicon or total alloying constitution over 7.5%. When Copper content is less than 4.6% and for all suitable castings alloys be sure alumium is tempered (such as -T4 or -T6).
COPPER  MIL-C-14550 . .
Copper in color and matte to a very shiny finish. Good corrosion resitance when used as undercoat. A number of copper processes are available, each designed for a specific purpose. Brightness (to eliminate the need for buffing); High speed (for electroforming); fine grain (to prevent casehardening); etc.   Unless otherwise specified  
Class 0 .001 - .005"  For heat treatment stop-off
Class 1 .001" For carburizing and decarburizing shield, also plated through printed circuit boards
Class 2
Class 3 .0005"  
Class 4 .0002" .0001"  
ELECTROLESS NICKEL  MIL-C-26074 . .
Similar to stainless steel in color. Plates uniformly in recesses and cavities (does not build up on edges) Corrosion resistance is good for coating over .001" thickness. Electroless nickel is used extensively in salvage of mis-machines parts. Also, for inside dimensions and irregular shapes (where assembly tolerances need uniformily provided by 'electroless" process).   Unless otherwise specified  
Class 1 Fe and Al alloys will be grade A As coated
Class 2 Steel and other base metals heat treatable to improve hardness
Class 3 Cu,Ni, Co alloys will be Grade B Aluminum and other base metals not heat treatable
Class 4   Aluminum alloy , heat treatable, processd to improve adheasion of the nickel deposit
Class A .0015" min
Class B .0005" min
GOLD  MIL-G-45204 . .
Yellow to orange color depending on proprietary process used. Will range from mattle to bright finish depending on basis metal. Good corrosion resistance, and has high tarnish resistance. Provides a low contact resistance, and is a good conductor. Has excellent solderability   Unless otherwise specified  
Type I   99.7% gpld min
Type II   99.0% gold min
Type III   99.9% gold min
Class 00 .00002" min Grade A 90 Knoop max
Class 0 .00003" min Grade B 91-129 Knoop
Class 1 .00005" min Grade C 130-200 Knoop
Class 2 .00010" min Grade D 201 Knoop and over
Class 3 .00020" min  
Class 4 .00030" min Type I (Grade A, B, or C)
Class 5 .00050" min Type II (Grade B, C, or D)
Class 6 .00150" min Type III (Grade A only)
HAE MIL-M-45202 . .
A corrosion, heat, and abrasion-resistant coating for magnesium. Suitable for use on all forms and alloys of magnesium. The color of HAE shall be lustreless brown and within range from number3010to 3035 of specification TT-C-595. The coating shall be able to withstand a 20% alt spray exposure of 196 hours. Type 1 Increase per side Light coating
Class A .0001" - .0002" Tan coating 
Grade 1 Without post treatment
Grade 2 With Bifluoride-didriomate treatment
Class C .0001" - .0005" Light green coating
Type II Heavy coating
Class A .0013" - .0017" Hard brown coating
Grade 1   Without post treatment
Grade 3   With bifluoride-dichromate seal
Grade 4   With bifluoride-dichromate seal and moist heat aging
Grade 5   Double application of Grade 4 post treatment
Class D .0009" - .0016" Dark green coating *
HARD ANODIZE MIL-A-8625 . .
Color will vary from light tan to black depending on alloy and thickness. Can be dyed in darker colors depending on thickness. Coating PENETRATES base metal as mush as builds up on the surface. The term THICKNESS includes both buildup and the penetration. provides very hard ceramic type coating. Abrasion resistance will vary with alloy and thickness of coating goo dielectric properties. Corrosion resistance is good, but recommend seal hard anodize in 5% dichromate solution where increased corrosion abrasion resistance is required. Where extreme abrasion resistance is required do not seal as some softening is encountered. Type III As specified on drawing. If not specified normal thickness shall be 0.002" Most aluminum alloys depending on process used. Where maximium serviceability or special properties are required, consult metal finisher for best alloy choice. Thick coatings (over .004") will tend to break down sharp edges. Typical applications, hydraulic cylinders, wear surfaces, actualic cylinders, wear surfaces, actuating cama, etc. Can be used instead of conventional anodixe for corrosion resistance and may be more economical in conjuction with other hard anodized areas.
Class 1   Non-dyed
Class 2   Dyed
LUBRICANT, SOLID FILM MIL-L-8937 . .
Used to prevent galling and seizure of metals. Lubricant covered by this specification is intended for use on aluminum, copper, steel and stainless steel, titanium, and chromium and nickel bearing surfaces. Useful where conventional lubricants are difficult to apply or retain or where other lubricants may be easily contameasily contaminated. cured lubricant film is highly resistant to conventional fluid lubricants.   Unless otherwise specified For sliding motion applications such as plain and spherical bearingsm flap tracks, hinges, threads, cam surfaces, etc. Do not use on materials adversely affected by exposure to temperatures of 300 F for 1 hour - on bearings containing rolling elements - or where tehre is potential contact with liquid oxygen
.0002" - .0005"
NICKEL  QQ-N-290 . .
There is a nickel finish for almost any need. Nickel can be deposited soft or hard - dul or bright, depending on processed used and conditions employed in plating. Thus hardness can range from 15-500 Vickers. Can be similar to stainless steel in color, or can be a dull gray or light gray (almost white) color. Corosion resistance is a function of thickness. Has a low coeffecient of thermal expansion - is magnetic. All steel parts having a hardness of Rc-40 or greater require a post bake at 375° +- 25°F for 3 hours.   Total thickness of copper and nickel NOTE: All steel parts having a tensile strength of 220,000 or greater shal not be nickel plated without specific approval of procuring agency. For Corrosion protection
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   For engineering applications
PASSIVATE MIL-S-5002 . .
A process designed to remove foreign metals from the surface of stainless and corrosion resistant steels and to promote natural tendency to surface to oxide. Does not change the apperance of the base metal. Process purifies surface and therefore improves corrosion resistance. Type I No dimensional change Low temperature
Type II Medium temperature
Type III High temperature
Type IV For steels containing large amounts (0.15 percent) of surfur or selenium.
Type V Anodic - For high carbon martensitic (440) steels
Type VI Low temperature (optional)
PHOSPHATE COATING; HEAVY DOD-P-16232 . .
      Heavy coating for corrosion and wear resist.
A coating for medium and low alloy steels. Gray to brack in color. Type M is more resistant than Type Z to alkaline enviroments. Type M can be used up to 250 F. Provides moderate corrosion resistant and prevents wear. Type M .0002" - .0004" Manganese phoshate base coating (min 16g/m2 or 11g/m2 when specified)+D134
Class 1 Supplementary preservative treatmentor coating, as specified.
Class 2 Supplementary treatment with lubricating oil conforming to MIL-L-3150
Class 3 No supplementary treatment
Class 4 Chemically converted (may be dyed to color as specified). With no supplementary coating or supplementary coating as specified. 
Type Z can be used up tp 200 Fto prevent galling in extrusion and depp drawing. Class 2 is good for corrosion resistance. Type Z .0002" - .0006" Zinc phosphate base coating (min 11g/m2)
Class 1 Supplementary preservative treatment or coating, as specified
Class 2 Supplementary treatment with preservative conforming to MIL-C-16173, Grade 1 or MIL-L-3150 as alternate for very small parts).
Class 3 No supplementary treatment
Class 4 Chemically converted (may be dyed to color as specified). With no supplementary coating or supplementary coating as specified. 
SILVER  QQ-S-365 . .
White matte to very bright in apperance. Good corrosion resisatnce, depending on base metal. Will tarnish easily. Hardeness caries from about 90 Brinnell to about 135 Brinnell depending on process and plating conditions. Solderability is excellent, but decreases with age. Best electrical conductor. Has excellent lubricity and smear characteristics for anti-galling uses on static seals, bushings, etc.   .0005" min unless otherwise specified  
Type I   Matte
Type II   Semi-bright
Type III   Bright
Grade A   Chromate post-treatment to improve tarnish resistance
Grade B   No chromate treatment
SULFAMATE NICKEL MIL-P-27418 . .
The plating conforming to this specification is intended to facillitate the formation of a seal between two metallic surfaces. PLATING HARDNESS not to exceed 150 Knoop hardness (500gm. Load) after annealling.   Unless otherwise specified  
  .0020"  
  "+-" ".0003" The nickel plating shall have columnar crystalline structure before anneating.
SULFURIC ANODIZE MIL-A-8625 . .
Color will vary with alloy. Aluminum with low alloying elements will show practically no color change. Best coating on aluminium for dyeing. Can be dyed practically any color or shade (Black, blu, red, etc.) Type II .00020" - .0010" All aluminium alloys, but do not use where solutions will entrap.
  FED-STD No 595 may be used as a guide for specifying color (approximate comparison only)
Salt Spray requirement is 336 hours (5% solution per method ASTM-B-117) Class 1   Non-dyed
Class 2   dyed
Minium weight for Type II coatings: Class 1: 600 Milligrams sq-ft. Class 2: 2500 Milligrams sq-ft.     NOTE: For wrought 2000 series and castings with 1% or greater copper min cfg. Wf. Shall be 1400 milligrams sq-ft.
TIN  MIL-T-10727 .  
Color is gray-white in a plated condition. Had very high luster in fused conditions. Soft, but is very ductile. Corrosion resistance is good. (Coated items should meet 24 hour 5% salt spray requirements.) Salderability is excellent. Tin is not good for low temperature applications 9changes structure and loses adhesion when exposed to temperature below 40 C).   As specified on drawing. Thickness guide not part of Spec. Electrodeposited. Use ASTM-B 545
Type I   Standard specification
Type II   Hot dipped
If a bright finish is desired to be used in lieu of fused tin, specify Bright Tin plate. Thickness ness can exceed that of fused tin and deposit shows excellent corrosion resistance and solderability.   .0001" - .00025" Flash for soldering
.0002" - .0004" To prevent galling and seizing
.0003" min Where corrosion resistance is important
.0002' - .0006" To preventformation of case during nitriding
ZINC ASTMB633-85 . .
Either a bright or dull finish is acceptable. Bright Zinc plating closely resembles bright chromium. However, bright zinc does not have the permanence of surface appearance. Zinc coated steel will not rust even when exposed by scratches because of the galvanic protection of the zinc. On weathering, zinc turns to a drab color. Zinc should be deposited directly on the base metal (Nickel is permissible undercoat if base metal is a corrosion resisting steel). Parts having a hardness greater that Rc-40 must be given a heat treatment prior to plating. Springs having a hardness over Rc-40 must be given an after plating baking of 375° +- 25°F for 3 hours. Fe/Zn25 SC4 .0010" The primary use of chromate finishes on zinc is to retard or prevent formation of white corrosion products on zinc surfaces
Fe/Zn13 SC3 .00050"
Fe/Zn8 SC2 .00030" The primary purpose of phospate coating on zinc is to provide a paint base
Fe/Zn5 SC1 .00020"
Type I   Without supplementary treatments
Type II   With supplementary chromate treatment
Type III   With supplementary colorless chromate treatment
Type IV   With phosphate conversion treatment
    Corrosion resistance requirements Type II 96 Hours Type III 12 Hours
ZINC NICKEL  AMS-2417 BAC-5637 . .
Dull matte gray or green irridescent. Type II acid or alkaline process. Excellent alternative for cadmium plate requirements. Meets and exceeds 96 hours salt spray test.   .0005" min  No supplementary treatment or supplementary chromate treatment.
  .0003" min
  .0002" min