FED QQ-N-290A Sulfamate Nickel Plating

ENS Technology are the sulfamate nickel plating experts. We provide electrolytic sulfamate nickel coatings to meet numerous specifications, including:

  • FED QQ-N-290A
  • AMS QQ-N-290
  • AMS 2424
  • MIL-P-24718
  • ASTM B689
  • and other industry or company standards

Often, sulfamate nickel plating specifications do not differentiate between bright and dull coatings. We can provide both bright and dull sulfamate nickel coatings, as your project requires.

Contact ENS today for turnkey sulfamate nickel plating service.

Sulfamate Nickel Coatings

Sulfamate nickel plating provides improved abrasion, wear, and corrosion resistance, and makes a very good undercoat for soldering electrolytically deposited gold. At its highest purity, the nickel used for these coating is 99.9% pure; electrolytic gold, at its highest purity, is 99.99% pure. The combination of nickel and gold creates a very reliable and consistent solderable material.

Sulfamate nickel coating specifications set the requirements for plating steel, aluminum, and copper substrates, as well as the standards for cleaning and the best underplating processes to prevent degradation of the base material.

Classes & Grades of Sulfamate Nickel Plating

There are two (2) different classes and seven (7) grades of sulfamate nickel plating used to meet various industry specifications. The class of a sulfamate nickel plating refers to the plating’s purpose; the grade of a sulfamate nickel plating refers to its thickness.


Class 1 refers to corrosion protective sulfamate nickel platings. Class 2 refers to engineering sulfamate nickel platings. Most of our clients require Class 1 coatings, but ENS has the capabilities to provide Class 1 or Class 2 sulfamate nickel coatings, as needed.

Grade (Thickness)

Sulfamate nickel coatings are graded A to G, based on thickness requirements.

  • Grade A: 0.0016” thickness
  • Grade B: 0.0012” thickness
  • Grade C: 0.001” thickness
  • Grade D: 0.0008” thickness
  • Grade E: 0.0006” thickness
  • Grade F: 0.0004” thickness
  • Grade G: 0.0002” thickness

Material & Hardness Requirements

For sulfamate nickel platings on steels, zinc, or zinc alloys, copper underplating of no less than 0.002” is required. For platings on copper alloys with greater than 40% zinc content, copper underplating of no less than 0.003” is required.

Sulfamate nickel plating requires embrittlement relief for all steel parts having a Rockwell Scale hardness of C40 or higher. The minimum requirement for embrittlement treatment is 375°F for three hours or more; treatment must be performed within four hours of plating. Embrittlement relief is important to ensure compliance with the applicable specification. Embrittlement relief testing can be performed on either “live” parts or test coupons, as customers prefer.

The Right Solution for Your Sulfamate Nickel Plating Specification

ENS Technology provides turnkey sulfamate nickel plating for parts and components of all shapes and sizes. Our dull sulfamate nickel coating formula contains no brighteners or additives that would decrease its purity and effectiveness as a pure metal deposit. Due to their chemistry, bright sulfamate nickel platings are less pure.

Adhesion Testing

Proper adhesion of sulfamate nickel plating requires that, when examined under approximately 4x magnification, neither the layers of nickel plating nor any electrodeposited undercoat shows separation from the substrate metal or each other when subjected to an adhesion test.

ENS’ adhesion testing for sulfamate nickel coatings involves scraping or shearing through the plating, down to the base metal, and examining it under 4x magnification for evidence of non-adhesion. If primary parts to be treated are not suitable for testing, customers should supply a test coupon of the same material and stock to ensure that the specification is met.

Contact Us for Sulfamate Nickel Plating

ENS Technology can provide sulfamate nickel platings to meet any specification. Request a quote on the coating(s) you need, or contact us to discuss your project.