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Armoloy Specifications

AMS QQ-N-290D

Electrodeposited Nickel Plating Specification

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Armoloy Specifications

What is AMS QQ-N-290D?

AMS QQ-N-290D is a U.S. military specification (formerly known as QQ-N-290) that outlines the requirements for electrodeposited nickel coatings on metallic substrates. Originally developed as Federal Specification QQ-N-290, it was later adopted by SAE International and reissued under the AMS (Aerospace Material Specification) system to meet aerospace, defense, and high-performance manufacturing needs.

This standard provides strict guidelines on:

  • Coating classes (by thickness)
  • Types (based on undercoating)
  • Service conditions
  • Adhesion and appearance
  • Hydrogen embrittlement relief (baking)

AMS QQ-N-290D ensures that nickel plating is uniform, adherent, corrosion-resistant, and suited for functional or decorative applications.

nickel plating on machined parts for ams qq-n-290d

The Role of AMS QQ-N-290D in Nickel Plating

AMS QQ-N-290D defines requirements for electroplated nickel, which provides:

  • Corrosion resistance
  • Wear protection
  • Enhanced solderability
  • Improved aesthetics

It is often used in combination with copper or other undercoats, depending on the substrate and performance demands.

Key Functional Areas:

  • Barrier Layer: Prevents diffusion of substrate elements into final coatings.
  • Engineering Surface: Used for dimensional buildup, wear surfaces, or brazing prep.
  • Decorative Finish: Enhances brightness and polish on consumer or aerospace parts.
AMS 2403 and ams qq-n-290d electrodeposited nickel plating on motorcycle exhaust

AMS QQ-N-290D Classifications

Classes (By Thickness)

  • Class 1: 0.0016 inch (1.6 mils)
  • Class 2: 0.0012 inch (1.2 mils)
  • Class 3: 0.001 inch (1.0 mil)
  • Class 4: 0.0008 inch (0.8 mil)
  • Class 5: 0.0005 inch (0.5 mil)
  • Class 6: 0.0003 inch (0.3 mil)
  • Class 7: 0.0002 inch (0.2 mil)
  • Class 8: 0.0001 inch (0.1 mil)

These classes are chosen based on the part’s end use, corrosion exposure, or tolerance allowances.

Types (Based on Undercoating):

  • Class I: Nickel only
  • Class II: Nickel over copper (for enhanced ductility or under soft substrates)
  • Class III: Nickel over copper plus bright nickel (common in decorative or dual-function finishes)

Testing and Quality Assurance

AMS QQ-N-290D specifies multiple quality checks to ensure plating integrity:

Adhesion Tests: Tape test, bend test, or thermal shock

Thickness Verification: Using magnetic gauges (ASTM B499), X-ray (ASTM B568), or coulometric methods

Hydrogen Embrittlement Relief: Mandatory baking for high-strength steels (per AMS2759/9)

Corrosion Resistance: Must pass neutral salt spray test (ASTM B117), particularly for parts with higher class ratings or outdoor use

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Industries That Use AMS QQ-N-290D

  • Aerospace: Hardware, engine parts, fasteners, and housings often require QQ-N-290D-compliant nickel to meet OEM and FAA standards.
  • Defense: Legacy systems and MIL-SPEC drawings frequently call out QQ-N-290D for plating, especially in high-reliability components.
  • Medical Devices: Non-reactive nickel finishes used on surgical or diagnostic equipment, sometimes over copper or stainless steel.
  • Electronics: Enhances the longevity and performance of molds, dies, and other precision tools.
  • Industrial Components: Rollers, shafts, and bearing surfaces plated with nickel for wear and corrosion resistance in harsh environments.
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Benefits of Working with an AMS QQ-N-290D Provider

Legacy specification expertise

Many aerospace and defense parts still call out AMS QQ-N-290D. Working with a compliant provider ensures you meet drawing and contract requirements without costly deviations

Dimensional precision

Nickel plating must meet strict tolerances. AMS QQ-N-290D providers are equipped to deposit and verify thickness to the micron level

Process control & documentation

Providers certified to AMS QQ-N-290D typically follow NADCAP, ISO 9001, or AS9100 quality systems for repeatability, traceability, and audit readiness

Post-plating deat treatment

Includes hydrogen embrittlement relief for high-strength steel parts in accordance with AMS2759/9 standards

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Specifications at Armoloy

Armoloy offers plating solutions that meet AMS QQ-N-290D to support both regulatory compliance and individual project needs. Explore common specifications and accreditations we work with, and contact us to find the right solution for your application.