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Service · Plating & galvanizing

Steel that stays steel, with the right coat on it.

Hot-dip galvanizing for anything that lives outdoors, electroplated zinc for indoor parts. Cut, bent and welded work goes straight on to the plating plant — you get finished parts back, without chasing a second supplier.

Hot-dip 45–85 µm · electroplated 5–25 µm · thickness checked on arrival
450 °CVENT HOLE
45–85 µm Hot-dip galvanizing
5–25 µm Electroplated zinc
~450 °C Molten zinc bath
Partner Plating step
How we run it

We run the finishing, you get finished parts

The plating itself is done by vetted partner plants — it needs a molten zinc kettle and its own effluent treatment, which does not belong inside a fabrication shop. We handle the ordering, transport both ways, coating-thickness checks on arrival, and the warranty on the batch. For you it stays one contract, one delivery.

  • Ordering and dealing with the plant
  • Transport both ways
  • Coating thickness measured on arrival
  • Warranty across the whole batch
Compare

Hot-dip or electroplated?

Two very different ways to put zinc on steel — different thickness, life and finish. Choose wrong and you either overpay or watch the parts rust through one wet season. This is how we advise customers.

Hot-dip galvanizing
Outdoor · structural
Electroplated zinc
Indoor · smaller parts
How it works
The whole part is dipped in molten zinc at about 450 °C
Zinc is deposited electrically from a bath, at room temperature
Coating thickness
45 – 85 µm, set by how thick the steel is
5 – 25 µm, chosen for where the part lives
Outdoor life
Decades with no repainting
A few years; needs a paint system to go outside
Finish
Matt grey, visible spangle, slightly rough and uneven
Bright and even; clear, yellow or black passivation
Threads and mating faces
Zinc fills threads — re-tap or mask before dipping
Tolerances hold; threads assemble as-is
Distortion
Thin sheet and asymmetric parts can warp from the heat
No heat, so no distortion
Typically used for
Frames, supports, railings, stairs, anything outdoors
Brackets, fasteners, enclosures, indoor parts
Priced by
Weight (kg) — heavier work gets cheaper per kg
Surface area or piece count
Coating spec

How thick the coating has to be

Thickness is not a free choice. In hot-dip, the zinc grows with the thickness of the steel underneath — heavier steel carries a heavier coat. These are the figures we inspect against when the batch comes back.

Hot-dip galvanizing

Steel thickness Zinc you can expect
≥ 6 mm 85 µm
> 3 – < 6 mm 70 µm
1,5 – 3 mm 55 µm
< 1,5 mm 45 µm

The coating grows with the base steel thickness; it cannot be dialled in freely. Small centrifuged parts — bolts and screws — come out thinner than this table.

Electroplated zinc

Where the part lives Thickness
Indoor, dry 5 µm
Indoor, humid 8 µm
Outdoor, sheltered 12 µm
Severe conditions 25 µm

Thickness is chosen for where the part will live, with a passivation layer that sets the colour and the white-rust resistance.

Passivation
  • Clear / blue — indoor parts that need to look bright
  • Yellow iridescent — better white-rust resistance
  • Black — where a dark, low-glare surface is wanted
Design rules

Designing a part that can be galvanized

Four things decide whether your part comes out of the kettle sound or scrap. Send drawings early and we will check them before anything is cut.

Hollow sections need vent holes

Tubes and closed boxes must have holes for zinc to flow in and out and for vapour to escape. Without them, trapped moisture flashes to steam at 450 °C and the part can burst in the kettle — this is a safety rule, and the plant will refuse the work. Put the holes diagonally opposite, as close to the ends as possible.

Thin sheet warps

Below 3 mm — and especially where thin sheet meets heavy steel in the same part — the heat of the kettle pulls the part out of shape. Design it symmetrically, add stiffening ribs, or move to electroplating plus paint if the part has to stay flat.

Plan the threads first

A 45–85 µm hot-dip coating fills threads. Either re-tap after galvanizing, tap oversize to the standard, or mask before dipping. Tell us up front so it is costed in — finding out after the batch is dipped means doing it twice.

Hard steel and hydrogen embrittlement

High-strength or hardened parts absorb hydrogen during electroplating and can crack later — sometimes weeks after assembly. The fix is a de-embrittlement bake straight after plating, as soon as possible. Tell us which parts have been heat-treated.

Send the drawings and we will check the finishing

Tell us whether the part lives indoors or out, whether it has threads, and whether it has been heat-treated. We will recommend the coating, put the vent holes into the drawing, and quote fabrication and plating as one price.

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REV 2026.07
SCALE 1:1
UNITS MM
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