Aluminum for Marine & Shipbuilding

Mg-alloyed plate resists seawater and welds without losing strength. This is the series classification societies expect to see on hull plate.

Get a Quote Grade guide

Specification

What Marine & Shipbuilding Specifies

Grades normally used	5083 · 5086 · 5754
Product forms	Plate · Sheet · Extrusion
Standards & approvals	ASTM B928 · EN 485 · DNV / LR / ABS approval available on request

Send the product form and the service condition — coating class, temperature, weld process, drawing tolerance — and the grade is confirmed against them before you commit to a die or a tonnage.

Grade by grade

What Each Grade Does in Marine & Shipbuilding

An application page that lists five grades without saying what each one is for is a catalogue, not a specification. These are the roles they actually play here.

Grade	The job it does here	Detail
5083	Hull and deck plate. H116 or H321 temper to ASTM B928, because plain H32 does not carry the intergranular corrosion requirement.	Specs →
5086	Superstructure and lighter structure, where 5083 is more strength than the design needs and formability matters more.	On request
5754	Interior, tanks and non-structural sheet — the easiest of the three to form and weld.	Specs →

Before you send the enquiry

Specification Mistakes That Cost Money Here

None of these is exotic. All of them arrive on real enquiries, and each one adds a round trip before a price can be issued.

1. Specifying 5083 by alloy only. Hull plate is accepted or rejected on temper and class approval, not on the four digits.

2. Ordering H32 for welded hull structure. H32 carries no intergranular corrosion requirement; H116 or H321 does.

3. Leaving the class society off the enquiry. DNV, LR and ABS add survey and stamping that change both price and lead time.

4. Assuming a 6xxx plate is a substitute. 6061 pits in salt immersion and is not accepted for hull structure.

Marine orders are usually accepted on three documents together: the mill certificate, the class approval certificate, and the heat number marked on the plate. If any one of the three is missing, the file is incomplete at survey.

Categories that serve it

What We Supply Into Marine & Shipbuilding

Aluminum Sheet & Plate

Rolled flat product from 0.2 mm foil stock to 200 mm plate.

Aluminum Coil

Continuously cast or hot-rolled coil for roll forming and stamping.

Aluminum Tube & Pipe

Seamless extruded, cold-drawn, and welded tube.

Aluminum Tread / Checker Plate

Raised-pattern slip-resistant plate: five-bar, three-bar, diamond.

Verification

What We Put in Writing for This Application

Mill test certificate to the class your file requires — 2.2 or 3.1 — carrying the actual mechanical test values for the heat.
Gauge and surface inspection recorded before packing; photos of the sealed container.
Where the market requires it, the classification society or coating test report with the issuing body named.

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Before you ask

Marine & Shipbuilding — Questions That Come Up

What temper should hull plate be ordered in?

H116 for sheet and plate in hull structure, H321 for plate from 6 mm upward. Both are ASTM B928 tempers carrying a controlled intergranular corrosion test. Plain H32 does not carry that requirement, which is why it is not accepted for hull work.

Does marine aluminium need classification society approval?

If the vessel is classed, yes. DNV, LR, ABS or whichever society the build specification names will survey the material and stamp the certificate. Name the society on the enquiry, because it changes both the documentation package and the lead time.

Is 5083 only for below the waterline?

No. 5083 is used for hull and deck, above and below the waterline. What changes above the waterline is usually plate thickness, and often a move to 5086 or 5754 for lighter structure where full 5083 strength is not needed.