? Where is your part right now?

Not made yetOne shop: we machine the part and plate it in the same order, so the surface that leaves the machine is the surface that gets coated. Plating adds a layer and grows the part, so masking and the allowance are decided before the part is cut rather than after.See the processes we run →Already madeSend the finished parts and say which faces have to be plated and which must stay bare. Plating is aimed by masking, not applied all over automatically - a face left unmasked gets coated, so tell us which is which before the parts arrive.Check if my parts qualify →Still comparing coatingsElectroplating is the general mechanism: a metal layer deposited by electrolysis. Nickel is only one of the metals that can be plated, and electro-less nickel uses a different mechanism entirely. The choice is driven by the corrosion, decorative or conductive duty the part has to meet.Which coating do I need? →

SURFACE FINISHING

Electroplating Service

A layer deposited by electrolysis Nickel, zinc, chromium, copper Steel, aluminium, stainless steel Hardware to aerospace

Electroplating is the establishing of metal layers to the parts by electrolysis. The thin layer of metal coating makes the parts excellent resistive to corrosion, wear, and abrasion. It is the parent process behind the plating pages on this site: nickel plating and zinc plating are two metals it can deposit, while electro-less nickel plating is a different mechanism that needs no current. Our published material table for this process is aluminium, steel and stainless steel.

Get a quote Which coating do I need?

By electrolysisHow the published description says the layer is formed

Corrosion, wear, abrasionWhat the published text says the coating resists

3 substratesAluminium, steel and stainless steel in the published table

3 industriesHardware, instrument and aerospace in the published text

A bright chrome-plated metal trim part with a polished ring, its mirror-like surface reflecting the light around it — A plated surface is the coating metal, not the substrate showing through. That is why a steel part, a zinc part and a chrome part can look nothing alike after plating - the finish is set by the metal that was deposited and by how thick the layer grew.

Where it fits

Electroplating deposits a metal layer by electrolysis in five steps

The part is the cathode. Current drives metal ions out of the plating bath and onto the surface, so what arrives on the part depends on the bath, the current and how long the part stays in it - not on how the surface already looks.

STEP 1Machine and finish the substrateThe geometry is cut first; plating only coats the surface, it does not fix a step or a gouge

STEP 2Clean and pre-treatCleaning and the pre-treatment set adhesion; aluminium in particular forms an oxide at once and normally gets a zincate layer first

STEP 3Plate by electrolysisYou are here - the part is immersed in the bath and current deposits the metal layer onto it

STEP 4Rinse and post-treatThe part is rinsed and dried; some coatings then get a chromate or passivation step for extra corrosion protection

STEP 5Inspect the coatingCoverage, thickness and appearance are checked - the layer has to be even enough for the duty it was specified for

The order matters because plating adds a layer, it does not remove one. Pre-treatment decides whether the layer sticks, and the current decides where it builds. Where current is weak - a recess or a blind hole - the layer can come out thin, which is the point where a different mechanism is worth comparing.

An illustration of the electroplating process showing a part in a plating bath with current passing through it

In electrolysis the part is the cathode. Metal ions from the bath take on electrons at the surface and deposit as metal, so the coating is built atom by atom out of the solution rather than applied as a film.

A step-by-step illustration of the electroplating process from cleaning to plated part — Pre-treatment, plating and post-treatment are separate steps. The first sets adhesion and the last sets corrosion protection, so both matter as much as the coating metal itself.

A row of plating tanks and busbars in an electroplating line — A plating line is a series of baths. The part moves between them, so the sequence and the rinse between each bath are part of the process, not a detail.

A copper electroplating bath with parts suspended in the solution — Copper is one of the metals plated this way. It is often laid down as a base layer before another coating, because it throws into recesses and conducts well.

An illustration comparing electrolytic and electro-less nickel plating side by side — The same metal, two mechanisms. Electrolytic nickel needs current; electro-less nickel is reduced chemically and needs none - which is why it covers complex shapes more evenly.

A comparison chart of zinc, chrome and nickel coatings side by side — Zinc, chrome and nickel are among the metals that can be plated, and the chart above shows how differently they read. Which one a part needs follows from the duty, not from the prettiest finish.

Fit check

Can we electroplate your part? Three things decide it

Whether the substrate conducts, whether the current can reach the faces that matter, and what the coating is actually there to do. The last one is where most plating jobs are won or lost.

Substrate and conductivity

Electroplating needs the part to carry current - the published table lists aluminium, steel and stainless steel, three conductive metals
Aluminium forms an oxide skin immediately, so a zincate pre-treatment is normally used before plating so the layer can bond
A non-conductive part such as a plastic must be made conductive first, or it cannot be plated by electrolysis at all
Steel and stainless steel plate directly once cleaned, though the exact pre-treatment depends on the alloy

The exact pre-treatment for a given alloy is confirmed per job.

Geometry and current reach

Current density is highest on edges and points, so the coating builds faster there
Deep recesses, blind holes and the inside of tubes see weaker current and can come out thinner than the outer faces
Hidden faces a fixture blocks are either masked deliberately or left uncoated
Where a part needs the same thickness everywhere, a current-driven process is the wrong tool for that face

Say which faces must be fully coated and which may be masked, so the fixturing and masking are planned around them.

What the coating has to do

The published text says the layer makes the part resistive to corrosion, wear and abrasion - those are three different duties and they point at different metals
A decorative requirement points at a bright metal such as chromium or nickel; a sacrificial corrosion duty on steel points at zinc
A conductive or a solderable surface points at copper, silver or tin
If the requirement is an oxide film, no added layer, or a coloured paint, plating is not the process to reach for

Tell us which duty dominates - corrosion, wear, appearance or conductivity - and the coating metal follows from it.

Specifications

Electroplating: a metal layer on steel, aluminium and stainless steel

Every value below is what we publish for this process. Where the shop has not confirmed a figure, the line says To confirm rather than a guess.

Mechanism

By electrolysisThe published description: metal layers are established on the parts by electrolysis

Substrates (published table)

3 listedAluminium, steel and stainless steel - the three materials in our table for this process

Coating metals

To confirmNickel, zinc, chromium, copper, tin, cadmium, silver and gold are the metals used for plating; which of them we offer for a given part is being confirmed

Texture (published)

Smooth, glossy finishAs published for this process - a bright decorative deposit; some coatings such as zinc dry matte rather than glossy

Colour

Set by the coating metalThe published table says n/a, so no single colour is claimed: nickel and chromium are bright, zinc is grey-white, copper is reddish

Standards

To confirmThe published table says n/a; the standard a plating job is run to depends on the coating and the application and is being confirmed per job

Thickness

To confirmThe published table carries no thickness figure; the layer grows with plating time and the target is set per job, so it is being confirmed

Effect on the substrate

Properties can changeThe published text states the substrate may change some physical and chemical properties based on the type of plating material and thickness

Why three rows say To confirm: the live table publishes no thickness and no standard, so neither is invented here. The two "n/a" cells become reasons instead - colour is not fixed for the family because it is set by the coating metal, and the standard is application-specific. The texture we do publish, and it comes across as smooth, glossy finish.

What it adds

Electroplating adds a layer - plan the allowance before plating

Unlike polishing, which removes material, electroplating is the opposite: metal is deposited on the surface and the part grows. That growth is small, but on a face carrying a tight dimension it is the whole tolerance.

Where it acts	What changes	Why it matters	What to do
Every plated face	A metal layer is added; the dimension grows	A dimension set exactly on nominal has no room for the coating.	State before or after plating on any dimension the coating reaches.
Threads and fits	The coating thickens the thread form	A plated thread can bind on its mating part if the growth is not allowed for.	Mask, allowance or chase the thread - name the threads that must fit.
Edges and corners	The layer builds faster where current is strongest	Edges and points can end up thicker than the flat faces beside them.	Flag sharp edges that must not thicken or round over.
Bores and recesses	Coverage can be thinner deep inside	Weaker current reaches a blind hole or a tube bore, so the layer may not be even.	Say which internal faces matter and how thick they must be.
Masked surfaces	No change where the process is blocked	Plating is aimed by masking: a face left unmasked gets coated.	Mark the faces to stay bare - masking is a per-face decision.
Substrate properties	Physical and chemical properties can change	The published text notes the substrate may change properties based on the plating material and thickness.	Name any property that must not change so it can be checked.

The direction of the change is published - material is added, not removed - but the amount is not: the live page carries no thickness figure, which is why the thickness row above says To confirm. The plating allowance has to be agreed with the shop, not assumed.

Tell us which dimensions are critical and which faces may be masked, and we will confirm the allowance before the parts are made.

Get a quote

Which coating

Which metal to plate - and when electroplating is the wrong route

Electroplating is the parent mechanism. The metal it deposits is a separate choice, and there is a group of parts where the answer is not electroplating at all. The last card below is that group.

An illustration of the electroplating process with a part acting as the cathode in a plating bath

Electrolytic plating - the parent route

A metal layer, deposited by current

The part is made the cathode and immersed in a bath of the coating metal. Current drives the metal out of solution and onto the surface. It is the general mechanism the nickel and zinc plating pages describe for one metal each.

Best for: conductive metal parts, a controlled layer on faces the current can reach

Not for: a non-conductive part with no conductive base, or a face a recess hides from the current.

A gold-plated part with a bright gold finish reflecting the light

Which metal - nickel is only one

Chosen for the duty

Nickel, zinc, chromium, copper, tin, cadmium, silver and gold are the metals used for plating. Nickel is only one of them - which one a part needs follows from whether the duty is corrosion, decoration or conductivity. See nickel plating and zinc plating for two specific cases.

Best for: matching the coating to the duty - zinc for sacrificial steel protection, nickel and chromium for wear and appearance, copper and silver for conductivity

Not for: assuming one metal fits every job. The duty picks the metal, so a decorative requirement and a corrosion requirement can end up on different coatings for the same part.

An illustration comparing electroplating and anodizing side by side

When electroplating is the wrong route

The not-applicable case

Electroplating deposits a metal layer driven by current. That is the wrong mechanism for several jobs. An oxide film on aluminium is grown from the metal itself by anodizing; a layer that must be perfectly even on a complex shape is deposited without current by electro-less plating; and a part that must not gain any surface layer is treated by heat treatment, which changes the steel itself.

Consider instead: anodizing for an oxide film on aluminium, electro-less nickel for even coverage without current, heat treatment where no layer is wanted

Not for: a part needing an oxide film on aluminium (use anodizing, a conversion coating, not a plated metal), a complex shape that needs the same thickness everywhere (compare electro-less nickel), or a part that must gain no surface layer at all (use heat treatment).

Coating metal	Chosen for	Typical look	Read more
Nickel	Corrosion and wear resistance with a bright decorative finish	Bright silver-white	Nickel plating
Zinc	Sacrificial corrosion protection for steel	Matte grey-white, often with a blue or yellow chromate	Zinc plating
Chromium	Hardness and a mirror-bright decorative surface	Bright mirror	Chrome vs nickel
Copper	Electrical and thermal conductivity; often a base layer under another coating	Reddish	Copper electroplating

Coatings are listed by the duty they are chosen for, not by a ranking. The right metal is the one that survives what the part will meet - and the exact set we run for a given part is confirmed per job.

Tell us the duty the part has to meet - corrosion, wear, appearance or conductivity - and we will confirm the coating metal and the route before you commit.

Get a quote

Pick or avoid

When electroplating is the right call - and when it is not

Pick electroplating when

The part is a conductive metal - the published table names steel, aluminium and stainless steel.
The job is to add a metal layer that resists corrosion, wear or abrasion, as the published text describes.
The requirement is decorative or conductive and is met by a metal deposit rather than a paint or an oxide film.
A small growth in size is acceptable, or the allowance can be planned before the part is machined.
The faces that must be coated are reachable by the current, or the ones that are not can be masked or accepted.

Avoid electroplating when

The part is non-conductive - a plastic must be made conductive first, or it cannot be plated by electrolysis at all.
The requirement is an oxide film grown from aluminium - that is anodizing, a conversion coating, not a plated metal.
The part needs the same thickness on every face of a complex shape - compare electro-less nickel, which is deposited without current.
The requirement is a coloured film, not a metal layer - use powder coating instead.
The part must gain no surface layer at all - use heat treatment, which changes the steel itself.

Not sure whether the part needs a plated metal, an oxide film, a paint or no layer at all? Send the drawing and say what the surface has to survive.

Get a quote

Design constraints

What decides whether the plated part comes back even

Four variables: whether the substrate conducts, how the current reaches the faces, the metal that was specified, and how much the layer is allowed to change the size.

Conductivity and pre-treatment

Electroplating needs the part to carry current, so the substrate has to be conductive. Aluminium forms an oxide immediately and normally gets a zincate layer first; steel and stainless steel plate once cleaned. A plastic part has to be made conductive before any of this can start.

Current reach and geometry

Current density is highest on edges and points, so the coating builds there fastest and slowest inside recesses and bores. An open, exposed face plates evenly; a blind hole or a deep recess can come out thinner. Where even coverage matters most, that is the case for comparing a current-free process.

Which metal was chosen

The coating metal sets the properties: the published text says the layer resists corrosion, wear and abrasion, but which of the three dominates depends on the metal. Nickel is only one option - the duty the part has to meet is what picks the coating, not the other way round.

Allowance for the added layer

Plating adds metal, so the part grows. On a cosmetic face that is nothing; on a thread or a precision bore it is the whole tolerance. The allowance, the masking and the before-or-after call on every dimension have to be agreed before plating.

Masking and fixturing

Plating is aimed, not dipped blindly. Faces that must stay bare are masked, and the fixture that holds the part also blocks some faces from the current. Both are choices, so a face left unmasked will be coated whether or not that was intended.

Post-treatment and handling

After plating the part is rinsed and dried, and some coatings get a chromate or passivation step for extra corrosion protection. A bright plated face also shows handling marks, so packing and the hand-over state are part of the finish.

Drawing notes

What to write on the drawing so the plating lands where you meant

Three lines carry the requirement: which metal is plated, which faces are coated, and which may be masked.

1.  PLATE WITH:  NICKEL / ZINC / CHROMIUM / COPPER    ____________  (DELETE ALL BUT ONE, OR WRITE THE METAL)2.  PLATE THE FOLLOWING SURFACES:    ____________________________________________  (SEE VIEW A)3.  MASK - DO NOT PLATE THE FOLLOWING FACES:    - ____________  (FACES TO STAY BARE)4.  DIMENSIONS ON PLATED SURFACES ARE    BEFORE PLATING / AFTER PLATING  (DELETE ONE)5.  COATING THICKNESS: ______ um  (TO BE CONFIRMED)6.  THREADS AND BORES:  ____________    STATE WHETHER THEY MUST STILL FIT AFTER PLATING.7.  INSPECT:  COVERAGE ON THE PLATED FACES, NO BARE OR    THIN AREAS ON A FACE THAT MUST BE FULLY COATED.

Examples only - replace every blank with your own requirement. The dimension line matters most: plating adds a layer, so a face that is already to size has to be marked as before or after, not left to chance.

Which metals

Which substrates can be plated - and what belongs to a different process

Our table for this process lists three conductive substrates. The coating metal is a separate choice, and some requirements belong to a process that is not electroplating at all.

Material	Electroplating	Notes	Use instead
Steel	Yes	In our published specification table for this process. A common substrate for a zinc or a nickel coating.	—
Aluminium	Yes	In our published specification table. Aluminium forms an oxide at once, so a zincate pre-treatment is normally used so the layer can bond.	—
Stainless steel	Yes	In our published specification table. For a corrosion duty alone on stainless, passivation cleans the surface without adding a layer.	—
Plastics and non-conductive parts	Needs a conductive base	Electroplating needs the part to carry current; a non-conductive surface must be made conductive first.	Electro-less nickel (deposited without current)
Aluminium needing an oxide film	Different process	Anodizing grows an oxide from the aluminium itself; it is a conversion coating, not a plated metal layer.	Anodizing
Parts needing no layer at all	Different process	Hardening changes the steel itself and adds nothing to the surface.	Heat treatment
Complex parts needing even coverage	To confirm	Electroplating throws more metal where the current is strongest, so a recess can come out thinner. Electro-less nickel deposits evenly without current - whether a given part is better plated or electro-less is confirmed per job.	Electro-less nickel
Coating metal (not the substrate)	To confirm	Nickel, zinc, chromium, copper, tin, cadmium, silver and gold are the metals used for plating; the set we run for a given part is being confirmed.	Nickel or zinc plating

Send the drawing with the material on it - if electroplating is not the right step for the substrate or the surface, we will say which one is.

Get a quote

Applications

Where a plated layer is doing the work

The published application areas for this process are hardware, instrument and aerospace parts, and other industries. These are the three cases behind those words.

Nickel-plated automotive wheels with a bright reflective finish

Automotive and transport

Wheels, trims and visible metal parts are plated for appearance and for wear, and the published application list names hardware and instrument parts first. The coating in these cases is doing two jobs at once - it looks the part and it resists the weather.

Zinc-plated metal parts laid out together with a uniform grey finish

Hardware and fasteners

Steel hardware is plated with zinc to give it sacrificial corrosion protection. The published text lists hardware first, and it is the case where the coating is chosen for the duty rather than for the look.

Plated steel connectors with a bright metallic finish

Aerospace and instruments

Instruments and aerospace parts are plated where the coating has to resist wear and corrosion while keeping a controlled surface. The published text names aerospace among the industries this process serves.

QA and documentation

What you get back with the parts

Purchasing usually needs paper as well as parts. Here is what we can state today and what is still being confirmed.

Available

Coverage inspection

The plated faces are checked for bare spots and for the even appearance the coating is specified for, which is how a plating result is judged.

Available

Clean of residues

Plating bath residues and the rinse water are removed before the part is packed, because a residue reads as a defect on a bright plated face.

To confirm

Coating thickness record

No thickness figure is published for this process; whether a measured coating thickness record can be supplied against an agreed target is being confirmed.

To confirm

Standard and specification

The published table says n/a for standards; the standard a given plating job is run to depends on the coating and the application and is being confirmed before it is quoted.

Electroplating is one family - where it sits beside the others

Electroplating is the parent mechanism. These pages cover the metals it can deposit, the process it is most often compared with, and the cases where a different family is the right one.

Electroplating in metal finishing

Where electroplating sits in metal finishing as a whole, and what it is used to achieve on a machined part.

Electroplating vs anodizing

The most common confusion on aluminium: plating adds a metal layer, while anodizing grows an oxide film from the metal itself. Different families, different results.

Types of metal plating

A survey of the coating metals - nickel, zinc, chromium, copper and the rest - and what each one is chosen for.

Electroplating vs electro-less plating

The mechanism comparison in full: current-driven deposition against chemical reduction with no current, and when the difference in coverage decides the choice.

Cadmium plating process

One specific coating, chosen for its own duty - a reminder that the coating metal, not the family, decides the properties.

Copper electroplating process

Copper as a coating: conductivity and a base layer under another deposit, plated by the same electrolytic mechanism this page describes.

Nickel plating and electro-less nickel plating

The two nickel routes side by side. Nickel is only one of the metals that can be plated; which route a part needs follows from how evenly the coating has to cover it. See also <a href="https://proleantech.com/surface-finishes/electro-less-nickel-plating/">electro-less nickel plating</a>.

All surface finishing processes

The hub page listing every process we run, so the plating family can be seen against the coating, conversion and machining families.

FAQ

Electroplating FAQ: the questions engineers ask us

What is electroplating?

Which materials can be electroplated?

Our published table lists aluminium, steel and stainless steel - three conductive substrates. The coating metal is a separate choice: nickel, zinc, chromium, copper, tin, cadmium, silver and gold are the metals used for plating. See the material table.

Is nickel the only metal that can be plated?

No. Nickel is only one of the metals used for plating. Zinc, chromium, copper, tin, cadmium, silver and gold are plated the same way, and which one a part needs follows from whether the duty is corrosion, decoration or conductivity. See which coating to choose.

What is the difference between electroplating and electro-less plating?

Electroplating drives the deposit with current; electro-less plating deposits it by chemical reduction with no current at all. The same metal can be laid down by either mechanism, and the no-current route covers complex shapes more evenly. See electroplating vs electro-less plating.

Is anodizing a kind of electroplating?

No. Anodizing grows an oxide film out of the aluminium itself - it is a conversion coating. Electroplating adds a separate metal layer on top of the substrate. Aluminium oxide is not a plating material. For an oxide film, the right process is anodizing.

Does plating add or remove material?

It adds. Plating deposits a metal layer, so the part grows a little. That is the opposite of polishing, which removes material. On a critical dimension the growth has to be allowed for, which is why the drawing should say whether a dimension is before or after plating. See what it adds.

How thick is the coating?

The live page publishes no thickness figure, so we do not quote one here. The layer grows with plating time and the target is set per job, so thickness is being confirmed rather than stated.

Will plating change the properties of my part?

It can. The published text states the substrate material might change some physical and chemical properties based on the type of plating material and thickness. If a property must not change, name it so it can be checked.

How do I get a quote?

Send the drawing, name the substrate and the coating metal you want, and mark which faces have to be plated and which must stay bare. Contact the team with the part details and we will come back with a quotation.

Get your electroplating quote

Upload a STEP, IGES or PDF drawing. Tell us the substrate, the coating metal, which faces have to be plated and which may be masked, and any dimension that must not move - we will come back with the coating and the sequence.

Get a quote Machine it first

What to send us

Drawing - 2D and 3D files (STEP, IGES or PDF).
Substrate - steel, aluminium or stainless steel; name any other material.
Coating metal - nickel, zinc, chromium, copper or another plate.
Which faces - plated, and which must stay bare (masked).
Critical dimensions - any face, thread or bore that must not move.
Duty - what the coating has to resist: corrosion, wear, appearance or conductivity.

All uploads are secure and confidential. Engineers review and reply with a quotation and lead time.