Electroless Nickel Plating Services

Electroless Nickel Plating Services (Company) per MIL-C-26074, ASTM B733 and AMS 2404

Electroless Nickel Plating Services

Advanced Plating Technologies is an industry leading company that provides electroless nickel plating services to MIL-C-26074, ASTM B733 and AMS 2404.  APT’s company expertise in providing exacting barrel, rack and vibratory electroless nickel plating services is currently employed in numerous industries including the medical, power transmission/distribution, petrochemical, and defense industries.

Advanced Plating Technologies, a Milwaukee, Wisconsin company, offers a wide range of electroless nickel plating services including both Type IV medium phosphorous and Type V high phosphorous deposits.  Post plate baking to attain high-hardness near HV1000 is available.  Our company excels in  heavy-build electroless nickel plating services and has provided electroless nickel plating services exceeding 0.005 inches per side.  Underplating with copper plating or electrolytic nickel plating is available to provide multi-layer duplex systems to enhance corrosion performance (reference:  What causes metals to oxidize or “rust” in the Plating Topics section).

Electroless Nickel Plating ServicesElectroless nickel is a unique coating that does not require an external source of electrons for deposition as in traditional electrolytic plating.  Rather, electroless nickel is a nickel-phosphorous alloy deposited by a chemical reduction (reaction) from hypophosphite on a catalytic substrate without the application of external current.  Since there is no applied current during deposition, electroless nickel deposits are free from the common nonuniformity of traditional electrolytic deposits and can cover even extremely complex geometries with excellent uniformity (reference: What are the advantages of electroless nickel over traditional electrolytic nickel in our Plating Topics section).

Any portion of a part that is equally wetted by the electroless nickel solution will plate uniformly including blind holes and the inner diameters of tubing or fittings.  The codeposited phosphorus in the deposit increases the lubricity over that of traditional nickel plating and the percentage of phosphorus in the coating also affects deposit properties such as magnetism, corrosion resistance and hardness.  In addition, a post-plate baking at temperatures above 500F can transition electroless nickel deposits from an amorphous as-plated state to a crystalline structure, greatly increasing hardness.

Reference the bullets below for the differences between medium and high phosphorus electroless nickel deposits.  Select the Electroless Nickel Technical Data PDF for a comprehensive listing of physical, mechanical and electrical electroless nickel deposit properties.Electroless Nickel Plating Services

  • High Phosphorous Electroless Nickel (> 10% P, Type V):  Semi-bright to matte appearance, non-magnetic, solderable with proper flux selection, and highly corrosion resistant.  Rc 48-55 (as plated), 66-70 (with heat treatment).
  • Medium phosphorous Electroless Nickel (6-9% P, Type IV):  Semi-bright to bright appearance, magnetic, good solderability and moderate corrosion resistance.  Rc 58-62 (as plated), 66-70 (with heat treatment).

The two most common electroless nickel plating services certified by Advanced Plating Technologies are MIL-C-26074, ASTM B733 and AMS 2404.  APT also can certify electroless nickel plating services to ISO 4527 and AMS 2405 as well as most company-specific electroless nickel specifications.  A summary of electroless nickel services per the MIL, ASTM and AMS specs is as follows:

Electroless Nickel Plating Services to MIL-C-26074

Electroless Nickel Plating Services Class 1:  As plated no subsequent heat treatment (a bake for hydrogen embrittlement relief is not considered heat treatment).
Class 2:  Heat-treated to obtain required hardness.  May be used on all metals not affected by heating to 500F and above.  Required hardness can be obtained per the following schedule:

°F Temperature                  Hours
500                                          4 or more
550                                          2 or more
650                                          1 to 1.5
750*                                        0.5 to 1*

* Advanced Plating Technologies’ preferred high-hardness bake schedule is 750F for 0.5 to 1 Hour as this provides the most complete and time-consistent transition of amorphous to crystalline deposit structure to attain high hardness.

Class 3:  Aluminum alloys nonheat-treatable, and beryllium alloys processed to improve adhesion of the nickel deposit.  Coated nonheat-treatable aluminum parts shall be heated for 1 to 1.5 hours at 375°F +/- 15°F to improve adhesion of nickel deposit.
Class 4:  Aluminum alloys, heat-treatable, processed to improve adhesion of the nickel deposit.  Coated heat-treatable aluminum alloys shall be heated between 240°F to 260°F for 1 to 1.5 hours to improve adhesion of nickel deposit.

Grade A – 0.0010-inch minimum deposit thickness
Grade B – 0.0005-inch minimum deposit thickness
Grade C – 0.0015-inch minimum deposit thickness

Electroless Nickel Plating Services to ASTM B733-04

Note:  ASTM B733-04 is markedly updated from ASTM B733-90 in that the coating Type specifies the phosphorous content of the coating.  ASTM B733-90 does not make this distinction.

Electroless Nickel Plating ServicesType I:  No requirement of phosphorous
Type II: 1-3% phosphorous (low phosphorous)
Type III: 2-4% phosphorous (low phosphorous)
Type IV: 5-9% phosphorous (medium phosphorous)
Type V: 10% or greater phosphorous (high phosphorous)

SC0:  Minimum Thickness 0.000004 in
SC1:  Light Service 0.0002 in minimum
SC2:  Mild Service 0.0005 in minimum
SC3:  Moderate Service 0.001 in minimum
SC4:  Severe Service 0.003 in minimum

Class 1:  As-deposited, no heat treatment.
Class 2:  Heat treatment at 260 to 400°C (500-752°F) to produce a minimum hardness of 850 HK100.
Class 3:  Heat treatment at 180 to 200°C (356-392°F) for 2 to 4-hr to improve coating adhesion on steel and to provide for hydrogen embrittlement relief.
Class 4:  Heat treatment at 120 to 130°C (248-266°F) for at least 1-hr to increase adhesion of heat-treatable (age-hardened) aluminum alloys (such as 7075) and carburized steel.
Class 5:  Heat treatment at 140 to 150°C (284-302°F) for at least 1-hr to improve coating adhesion for aluminum, non age-hardened aluminum alloys, copper, copper alloys and beryllium.
Class 6:  Heat treatment at 300 to 320°C (572-608°F) for at least 1-hr to improve coating adhesion for titanium alloys.

Electroless Nickel Plate Services – AMS 2404

Note: AMS 2404 supersedes AMS-MIL-C-26074 which employs Grade designations to convey thickness requirements.  See 8.13 for a complete cross reference from AMS-MIL-C-26074 callouts to the technically identical provisions within this specification (AMS 2404) in order to comply with the purchase order requirements.

Electroless Nickel Plating Services

Class 1:  Except for hydrogen embrittlement relief, no post plating thermal treatment.
Class 2:  Thermal treatment at 450°F (232°C) or above to harden the deposit.
Class 3:  Thermal treatment at 375°F (191°C) to improve adhesion for nonheat-treatable aluminum alloys and beryllium alloys.
Class 4:  Thermal treatment at 250°F (121°C) to improve adhesion for heat-treatable aluminum alloys.

1.3.1 Unless a specific class is specified, Class 1 shall be supplied.

3.1.1 Stress Relief Treatment – Steel parts having a hardness of 40 HRC or higher and which have been ground after heat treatment shall be cleaned to remove surface contamination and suitable stress relieved before preparation for plating.  Unless otherwise specified, the stress relief temperature shall not be less than 275°F (135°C) for not less than five hours for parts having hardness of 55 HRC or higher or not less than 375°F (191°C) for not less than four hours for other parts. When Class 2 is specified, parts shall be heated to a selected temperature within the range of 450 to 800F and held for sufficient time to increase hardness of the deposit.  See 3.4.4 and 8.6.  Hydrogen embrittlement relief (3.3.1) may be omitted if Class 2 hardening is accomplished within four hours after plating. When Class 3 is specified, parts shall be heated to 375°F +/- 15°F for 1 to 1.5 Hours. When Class 4 is specified, parts shall be heated to 250°F +/- 10°F for 1 to 1.5 Hours.

3.4.1 Thickness

Unless otherwise specified, minimum thickness of the nickel coating shall be 0.0010 inch for aluminum based alloys, 0.0005 inch for copper, nickel, cobalt, titanium and beryllium alloys and 0.0015 inch for iron-based alloys.

3.4.4 Hardness

Class 2 plating shall be not lower than 800 HK100, or equivalent determined in accordance with ASTM E384.

3.4.7 Composition

Electroless Nickel Plating ServicesThe cognizant engineering organization may specify a phosphorus content range of the deposit.  When specified, the composition of the deposit shall be determined by a method acceptable to the cognizant engineering organization.

8.6 The following thermal treatments have been used to achieve Class 2 hardness:

°F Temperature                  Hours
450                                          4, minimum
500                                          4, minimum
550                                          2, minimum
650                                          1 to 1.5
750*                                        0.5 to 1*

 * Advanced Plating Technologies’ preferred high-hardness bake schedule is 750F for 0.5 to 1 Hour as this provides the most complete and time-consistent transition of amorphous to crystalline deposit structure to attain high hardness.

8.13 AMS-MIL-C-26074 and its predecessor specifications encourage the use of Grade designations to specify thickness as follows:Electroless Nickel Plating Services

Grade A 0.0010 inch minimum
Grade B 0.0005 inch minimum
Grade C 0.0015 inch minimum




Electroless Nickel Plating Services – Why APT?

AMS 2404
ISO 4527
Most Company Specifications

Finish Type:
Medium Phosphorous
High Phosphorous

Substrates Plated On:
Ferrous: All Ferrous Alloys Including Mild Steel, Stainless Steels, Hardened Steels & Tool Steels
Cuprous: All Cuprous Alloys Including Pure Copper, Copper Alloys Including Tellurium & Beryllium, Brass, Nickel-Silver
Aluminum: All Aluminum Alloys Including Wrought, Cast and Proprietary Alloys (MIC-6)
Exotics: Inconel, Pure Nickel (Nickel 200), Cobalt-Chrome (MP35N), Kovar, Monel, Hastalloy, Monel, Lead

Part Size Limitations:
32 Inches x 30 Inches x 14 Inches (Aluminum & Brass)
32 Inches x 42 Inches x 20 inches (Copper & Steel)

Underplates Provided:
Electrolytic Nickel

Heat Treatments:
Hydrogen Embrittlement Bakes
Stress Relieving Bakes
High Temperature Bakes up to 750F

Selective Loose Piece Plating
Sheet Product (Chemically Milled/Etched Sheets)
Segmented Strips (Frets)