If you work with landing gear, hydraulic actuators, engine shafts, or precision fasteners, you already know these components are a target for failure. To avoid such disasters, hard chrome plating is what we reach for when a part needs wear resistance and low friction. This can be used for landing gear struts and actuator rod components. Electroless nickel plating is what we use when a part has a complicated shape and needs an even deposit and reliable corrosion protection. This is often used in fuel injectors, fasteners, and hydraulic bores. These aerospace components require hard chrome plating or electroless nickel plating.
Why Aerospace Parts Need a Protective Finish
Aircraft parts are in constant use and require perfection. The landing gear assembly takes the full weight of the plane each time it touches down, experiences high heat on the tarmac and frozen at altitude within the same flight. We count on it to work reliably.
When it comes to bare steel and aluminum, these metals cannot hold up to that type of intensity on their own. That is why engineers add a surface finish, such as hard chrome plating or electroless nickel plating, to give the part the wear resistance and corrosion protection the base metal cannot deliver on its own.
At EN-CHRO Plating for more than 40 years, we’ve worked in various industries protecting all size components with hard chrome plating and electroless nickel plating. In terms of hard chrome plating, it’s the solution to use for heavy wear and high stress corrosion resistance properties. On the electroless nickel plating side, this is the solution when you need the components to be evenly covered right down into threads, cavities, and internal channels. If you are unsure which one to use, or which is the best application for your parts, let us know, and we’ll provide the consultation you need to make an informed decision.
What Hard Chrome Plating Actually Does
Hard chrome plating is an electroplated coating, meaning we run a current through a chromium bath to bond a dense, hard layer of chromium onto the part, landing somewhere around 68 to 72 on the Rockwell C hardness scale.
This hardness gives you abrasion resistance, a low friction coefficient, and strong resistance to galling, which is the surface damage you get when two metal parts rub against each other under load. It is why hard chrome plating is the solution for parts under constant sliding contact, like piston rods and gear shafts.
Hard chrome is deposited from .001 inch up to .010 inch or more depending on what the part will face out in service, with a lighter flash chrome option available for more delicate parts that do not need the full buildup.
What Electroless Nickel Plating Actually Does
Electroless nickel plating skips the electrical current entirely. Instead, a chemical reaction deposits a nickel phosphorus layer onto the part, which means the coating builds up evenly across the whole surface, including blind holes, internal bores, and tight corners.
That even coverage is exactly why electroless nickel plating is used for complex sizes and shapes. It forms a dense, low porosity barrier with no weak spots, so moisture and corrosive fluids do not get into those small crevices where moisture can begin to hurt the process.
In addition, high phosphorus deposits, around 10 to 13 percent, hold up best in acidic or otherwise harsh environments. Mid phosphorus deposits is best for both hardness and corrosion resistance for general use, and low phosphorus deposits focuses on hardness where wear is the bigger concern.
The Aerospace Parts that Need Hard Chrome Plating
Hard chrome plating is the right choice whenever a part deals with constant sliding friction, repeated loading, or mechanical wear. Here is where it shows up most.
Landing gear struts and pistons take the force of every takeoff and landing. The pistons will need a hard, low friction surface that will not score as the piston moves in and out of its cylinder.
Hydraulic actuator rods extend and retract nonstop to move flight control surfaces, flaps, and landing gear doors. If there are any rough spot on the rod, it can chew through the seals holding the hydraulic fluid in.
Engine shafts and gearbox parts spin under heavy load, and the anti galling properties of hard chrome plating help keep them from seizing under high torque.
Precision shafts and rollers used in the equipment that builds and assembles aerospace parts also lean on hard chrome to hold tight tolerances through long production runs.
The Aerospace Parts that Need Electroless Nickel Plating
Electroless nickel plating tends to be the chosen solution when a part has a complicated shape, needs even corrosion protection everywhere, or has to stand up to aggressive fluids like jet fuel or hydraulic fluid.
Fuel injectors and other fuel system parts have tight internal passages.
Fasteners, connectors, and smaller hardware benefit because the coating applies evenly on threads and recessed features, protecting the whole part.
Turbine and engine components exposed to high heat can use electroless nickel plating since the coating stays stable at elevated temperatures while still fighting off corrosion from combustion byproducts.
Internal hydraulic bores and valve bodies with tricky internal shapes need electroless nickel plating. A hard chrome bath struggles to build up evenly deep inside a bore, which leaves thin spots that invite corrosion.
Hard Chrome Plating Versus Electroless Nickel Plating
| Property | Hard Chrome Plating | Electroless Nickel Plating |
| Deposition method | Electroplating with applied current | Autocatalytic chemical reaction |
| Typical hardness | 68 to 72 Rockwell C | Varies by phosphorus content and heat treatment |
| Coverage uniformity | Thinner in recesses and blind holes | Uniform across complex geometry |
| Best known for | Wear resistance and low friction | Corrosion resistance and uniform coverage |
| Typical thickness range | .0005 inch to .010 inch or greater | Varies by class, generally thin and precise |
| Common aerospace parts | Landing gear struts, actuator rods, engine shafts | Fuel injectors, fasteners, valve bodies, turbine parts |
| Maximum service temperature | Suited to high mechanical load environments | Stable up to 1000 degrees
Fahrenheit |
How to Choose
It usually comes down to what kind of stress the part is under. If a part slides, spins, or takes repeated mechanical impact, hard chrome plating is usually the better choice because of its hardness and low friction.
If a part has a complicated internal shape, sits in a corrosive environment, or needs consistent thickness everywhere, electroless nickel plating is usually the smarter choice because of its even coverage and tight, low porosity barrier.
Frequently Asked Questions
We want you to be comfortable working with the experts at EN-CHRO Plating. Here are a few questions we would like to answer for you now. If you have more that you would like to ask, feel free to contact us.
Is hard chrome plating stronger than electroless nickel plating? Hard chrome is generally harder and holds up better to wear, while electroless nickel usually wins on corrosion resistance thanks to its even, low porosity coating. However, if you heat treat the electroless nickel plating, it can get very close to the hardness of hard chrome.
Can electroless nickel plating go on aluminum aerospace parts? Yes. The coating works on lightweight aerospace structures as well as steel parts.
Why do landing gear parts use hard chrome instead of electroless nickel? Landing gear struts and pistons deal with nonstop sliding friction under heavy mechanical load, and hard chrome’s hardness and low friction make it the more durable option for that specific kind of wear.
Experienced with the Process Matters
Picking the right coating is only half the battle. Getting consistent results depends on having an experienced group of hands-on experts with the process control, testing equipment, and quality systems to hit spec on every single part, every time.
We have applied hard chrome and electroless nickel finishes at EN-CHRO Plating for more than four decades, across industries where a part failing under stress simply is not an option. That kind of hands-on process experience, more than any spec sheet, is what keeps critical parts working long after they leave our shop. Aerospace components that require hard chrome plating or electroless nickel plating can be best served at EN-CHRO Plating located in Melrose Park, IL.