Electroless Nickel

Capability

Electroless Nickel Plating

Electroless nickel (EN) is a chemical plating process, not an electrical one. The nickel-phosphorus alloy is deposited through an auto-catalytic chemical reduction reaction, with no current flowing through the bath. That single difference unlocks the property the rest of the industry can't match: uniform plating thickness across the entire part — threads, recesses, blind holes, internal surfaces, complex curves.

The deposit is hard, corrosion-resistant, well-adhered, and performs reliably across both metallic and non-metallic substrates. After post-plating heat treatment, EN hardness can be driven to 1000 HV or higher, making it one of the most versatile finishes available for precision and wear-critical hardware.

Deposit

Ni-P Alloy

Auto-catalytic chemical deposition

Standard Thickness

0.0002–0.0007"

~5–18 µm, higher available per spec

Post-Treat Hardness

Up to 1000 HV

With heat treatment

Coverage

Uniform

On complex geometry & recesses

Phosphorus Content

Three EN Formulations, Three Performance Profiles

Electroless nickel coatings are categorized by the phosphorus content of the deposit. Each formulation delivers a different combination of hardness, corrosion resistance, and finish appearance. CMC runs all three.

Low Phosphorus

2–5% P

Greatest As-Deposited Hardness

Highest hardness of the three formulations directly off the line, and the strongest corrosion resistance in alkaline environments. Common for wear-critical applications and parts where post-plate heat treatment isn't an option.

Mid Phosphorus

6–9% P

Bright Finish, Broad Application

Consistently bright deposits and the best balance of corrosion resistance across a wide range of environments. The industrial workhorse formulation, suitable for most precision and corrosion-protection applications.

High Phosphorus

10–13% P

Best Corrosion in Acidic Service

Best corrosion resistance in acidic environments, including oil and gas, chemical processing, and food and beverage applications. Smooth amorphous deposit, non-magnetic, with extended salt-spray performance.

Where Electroless Nickel Fits

Common Applications

Electroless nickel is the answer whenever a part needs uniform, high-performance protection that can't tolerate dimensional drift or coverage gaps in complex geometry. Typical applications include:

  • Hydraulic and fluid system components — fuel lines, manifolds, heat exchangers, valves, fittings, and the tubular hardware where internal coverage matters as much as external
  • Drivetrain and motion components — pistons, bearings, gears, cams, motor shafts, thrust washers, differential pins, shock absorbers
  • Electrical and electronic hardware — busbars, electrical lugs, connectors where uniform thickness and corrosion resistance combine
  • Precision and tight-tolerance assemblies — parts where electroplating's thickness variation would put fits, threads, or critical dimensions out of spec
  • Underplate for tin or tin-zinc on aluminum — EN provides the diffusion barrier and surface preparation that lets solderable finishes adhere reliably to aluminum substrates

Hardness on Demand

Post-Plating Heat Treatment

Electroless nickel is hard as-deposited, with low-phosphorus formulations delivering the highest off-the-line hardness. For applications that need true wear-grade hardness, post-plating heat treatment precipitates nickel phosphide phases within the deposit, driving hardness up to ~1000 HV (comparable to industrial hard chrome) while maintaining EN's uniform coverage and corrosion performance.

The heat treatment cycle and target hardness are specified per part and per program. CMC's process engineering works through the trade-offs (substrate compatibility, dimensional change, residual stress) before scheduling, so the finished part lands where the print needs it.

Specifications & Standards

Standards We Can Meet

ASTM B733

Standard specification for autocatalytic (electroless) nickel-phosphorus coatings on metal

AMS-2404

Aerospace material specification for electroless nickel plating

AMS-2405

Aerospace specification for low-phosphorus electroless nickel plating

MIL-DTL-32119

Military detail specification for electroless nickel coatings

IATF 16949

Automotive quality management process control across all facilities

RoHS, REACH

Modern EN chemistries fully compliant with global directives

Specifying electroless nickel for a part?

Send us a drawing, an aerospace or industrial specification, or a part description. We’ll match the right phosphorus formulation, the right thickness, and the right heat treatment to your geometry, your service environment, and the standard your program runs to.