Most machined, formed, seamless piercing or stamped metal parts require a metal finishing process to fend off corrosion, minimize wear from friction, and often enhance additional properties such as lubricity, hardness, and appearance. Two of the most commonly used metal-finishing techniques are hard (functional) chrome plating and electroless nickel plating. We will do our best to compare nickel plating vs. chrome plating. Let’s start with some of the reasons why a metal part manufacturer would choose to coat a metal part before shipping the order on to the assembly stage.

Five Key Reasons to Apply a Metal Coating Post-Fabrication

Manufacturers will typically choose to apply a finishing layer after machining, forming, seamless pipe making or stamping for several primary reasons:

1. 1. Corrosion resistance enhancement – many steel alloys, including A-36, are vulnerable to oxidative attack, especially in acidic or variable environments.
   2. Wear resistance – to reduce abrasion, galling, and surface fatigue, especially where parts are sliding or rotating.
   3. Improved lubricity – coatings can reduce friction coefficient, enhancing performance and extending service intervals.
   4. Dimensional restoration or tolerance refinement – plating can build up worn or undersized features and bring parts into spec without re-machining.
   5. Appearance or decorative utility – in visible or consumer-facing components, a shiny, uniform finish (chrome or nickel) may be desired—but note not all metals accept such finishes safely, especially when using hexavalent chrome or certain nickel composites.

Not all metals, nor all finishing chemistries, are suitable for a metal finishing process like functional chrome plating. For instance, hexavalent-chrome baths can pose adhesion or hydrogen embrittlement concerns on high-strength steels. Electroless nickel plating may have compatibility issues on certain copper alloys or untreated cast iron. Let’s take a look at some of the Types of Metal that we often see in our plating shop in Texas. Know that we focus primarily on Electroless Nickel Plating services. If you are looking for a hard chrome plating shop near Dallas, TX, we will introduce you to one of our chrome plating partners or speak to you about the benefits of electroless nickel plating as an alternative to chrome.

Types of Metals Suitable for Chrome or Nickel Plating

Comparing Hard Chrome vs Nickel Plating Under Typical Rainy Conditions

Let’s Understand Corrosion Rate First

Corrosion rate is a measure of how quickly a metal deteriorates when exposed to environmental factors—in this case, rainy conditions that provide both moisture and oxygen. When rainwater contacts metal, it can act as an electrolyte, accelerating electrochemical reactions that break down the surface of the material.

What’s the Impact of Corrosion on a Metal Part made from Mild Steel?

Rain in Texas tends to have a lower pH than 7. Let’s assume a machined part made from mild-steel (A-36) processed on a 5-axis milling center, with no post-machining heat treatment, is exposed to typical corrosive conditions. For this example, we will use a rainy season averaging 10 days per month with an average pH ~ 5.6.

The corrosion rate is usually expressed in units such as millimeters per year (mm/yr) or mils per year (mpy), and it represents the average thickness of metal lost over time. A higher corrosion rate means the metal will lose strength, mass, and structural integrity more quickly.

Therefore, for this example, your metal part will much quicker without any corrosive protection. But let’s compare these two types of coatings using our example part in rainy conditions:

• • Hard chrome plating tends to offer solid wear resistance, but its corrosion protection is typically less uniform—especially on complex geometries—and is vulnerable to micro-cracking or defects. Practical corrosion rate in mild-acid rain might be on the order of 2–4 mils/year, depending on thickness and imperfections.
  • Electroless nickel plating, by contrast, delivers a uniform, defect-resilient coating even on complex shapes. It generally offers better corrosion resistance—industry sources note that electroless nickel plating is “more resistant to corrosion” than hard chrome (HCS Plating, WayKen). In conditions like these, expect corrosion rates closer to 1–2 mils/year, sometimes lower with higher phosphorus content or post-plate passivation.

In summary, electroless nickel plating typically halves the corrosion rate compared to hard chrome, thanks to its coverage uniformity and chemical resilience.

Electroless Nickel vs Hard Chrome – A Cost Comparison

According to recent cost breakdowns:

• Electroless nickel plating typically runs $7–$20 per square foot, depending on part complexity and desired coating thickness (Limmco Plastic Injection Molding).
• Chrome plating tends to be more expensive—often in the range of $20–$50 per square foot, due to multi-step processes of polishing, and waste-handling needs (ChemResearch Co).

Thus, electroless nickel plating is demonstrably more affordable than hard chrome processes.

Environmental Friendliness & Toxicity of Both Coatings

• • Hexavalent chromium (Cr⁶⁺) is highly toxic and carcinogenic for those employees that are in contact with the coating process. OSHA documents show links between exposure and increased risks of lung, nasal, and sinus cancers (OSHA). Exposures may also cause contact dermatitis, skin ulcers, and asthma-like symptoms (OSHA, WA Labor & Industries). OSHA’s fact sheet outlines permissible exposure limits and highlights hard chrome electroplating baths as a particularly high-risk source (OSHA).
  • The EPA classifies hexavalent chromium as a hazardous air pollutant, and electroplating operations are subject to strict effluent and air-emission controls. Chromium mist and wastewater require complex treatment protocols. (Wikipedia, US EPA).

Electroless Nickel Coating Process: A More Environmentally Friendly Solution

By contrast, electroless nickel plating, when operated under proper wastewater treatment and filtration best practices, is generally more environmentally manageable. One industry overview emphasizes the use of best management practices to mitigate emissions and waste liability (NMfrc, Regulations.gov).

For shop employees: electroless nickel poses far fewer respiratory or carcinogenic risks compared to hexavalent chrome fumes—especially if facilities ensure good ventilation, personal protective equipment, and chemical handling protocols.

Chrome Vs. EN on Uniformity & Thickness Consistency

• • Hard chrome plating is an electrolytic (electroplating) process—thickness varies with current distribution. On irregular shapes, blind holes, or inside bores, plating thickness can be uneven, and may require later machining or polishing.
  • Electroless nickel plating is a chemical deposition (autocatalytic) process that coats uniformly, regardless of geometry—internal cavities, tubing bores, complex profiles get consistent layer thickness (ChemResearch Co,).

In precision-sensitive assemblies, where consistent dimensional tolerances are critical, electroless nickel plating is clearly superior. If precision measurements are important downstream, selecting electroless nickel plating ensures uniform bump build and predictable final dimensions.

While hard hexavalent chrome plating has advantages in extreme hardness and a brighter appearance, the evidence strongly supports that electroless nickel plating is the superior overall technology—offering:

• • Lower production cost
  • Improved corrosion resistance (especially in acidic, real-world environments);
  • Safer and more sustainable environmental and workplace profiles; and
  • Significantly better coating uniformity on complex geometries, preserving precision and easing assembly downstream.

For modern steel parts requiring durable, corrosion-resistant, precise tolerences, and cost-effective finishing—particularly where environmental and workforce health aren’t to be compromised—electroless nickel plating is demonstrably the superior coating.