Marine & Offshore

Salt air and spray corrode ordinary steel from the first week, and the Red Sea and Arabian Gulf coasts are among the warmest, saltiest environments a fabricator can work for. Marine work therefore starts from material choice, 316L and above, and continues through fabrication details that avoid crevices and trapped water. We supply and process marine-grade stainless and aluminium, and fabricate structural steelwork and piping for ports, shipyards, coastal plants and offshore installations in Saudi Arabia.

Laser-cut and formed components in marine grades are produced from our own stock, so smaller marine fabricators, boat builders and maintenance contractors can source processed parts without holding alloy inventory themselves. The sections below explain what we make, how the grade is chosen for splash, immersion and atmosphere, and what a good enquiry looks like.

What we fabricate and supply for marine work

• Steel structures: jetty and quay steelwork, gangways, walkways, handrails, equipment skids and support frames in coated carbon steel or stainless.
• Laser-cut components: deck fittings, brackets, plates, hatches, panels and guards cut from 316L, duplex and marine aluminium to the drawing file.
• Bending and forming of cut parts into channels, angles, trays and enclosures, with the bend radii the grade needs.
• Process piping: seawater cooling, ballast, firewater and fuel spools and manifolds in stainless, duplex and copper-nickel alternatives, welded to qualified procedures.
• Electropolishing and passivation of finished parts, so the passive layer that resists salt is intact when the part goes to sea.

Choosing the grade for the exposure

Atmospheric exposure near the coast is where most marine metalwork lives, and 316L is the working floor: it tea-stains in heavy salt fog but holds its integrity where 304 pits. The article on why 304 stains near the Saudi coast shows what the difference looks like in practice. Where the surface is warm, sheltered from rain and rarely washed, or where the finish must stay bright, duplex 2205 is the safer specification.

Splash zone and immersion move the range up. Seawater piping, pump components and fittings that sit wet are specified in super duplex 2507 or 2205 rather than in austenitic grades, because crevice corrosion under deposits and gaskets is the failure mode and the duplex grades resist it far better. The PREN calculator ranks candidates from their composition, and the grade pages give the chemistry and resistance class with sources.

Aluminium has its place on deck and superstructure. 5083 and 5086 are the marine plate alloys, 5052 serves lighter sheet work and 6082 covers extrusions and machined fittings. Wherever aluminium meets stainless fasteners or fittings, isolate the joint: the article on galvanic corrosion between aluminium and stainless explains why and how.

Fabrication details that keep salt out

Grade alone does not protect a part. Crevices formed by lap joints, intermittent welds, unsealed fastener holes and rough weld profiles trap salt water and start corrosion under it, so marine detailing uses continuous welds, sealed or drained pockets and ground, blended weld profiles wherever the drawing allows. Carbon steel tooling never touches the stainless surface, and wire brushes, grinding discs and lifting gear are dedicated to stainless so no free iron is embedded.

After fabrication, parts are pickled and passivated or electropolished, which removes weld heat tint and embedded iron and restores the passive layer. Coated carbon steel structures follow the project's marine painting specification, with surface preparation and film build inspected and recorded.

What a good enquiry contains

For processed parts: the drawing files, the grade and thickness, the quantity, the finish to be protected and whether bending or welding is included. For structures and piping: the design drawings, the grade, the coating or surface treatment, and whether the item is atmospheric, splash or immersed. Weights for budgeting can be checked on the sheet and plate weight calculator. When the scope is defined, send the enquiry with the exposure named; it changes the grade we offer.

Common questions

Is 316L good enough for marine use, or should we go to duplex?

316L is the working grade for coastal atmosphere and for parts that are washed by rain or hosed down. It is not the answer for continuous immersion in warm seawater or for tight crevices that stay wet, where duplex 2205 or super duplex 2507 is specified. Tell us whether the part is atmospheric, splash or immersed and we will recommend against that.

Can you cut and form marine aluminium as well as stainless?

Yes. Marine aluminium plate and sheet are laser-cut and formed with dedicated tooling, and the alloy and temper are confirmed on the drawing before cutting. Where the aluminium part will be fixed with stainless fasteners, we flag the galvanic couple and propose isolation on the drawing rather than leave it to site.

Do the parts arrive passivated?

Fabricated stainless parts are pickled and passivated as standard, or electropolished where the specification asks for it, so the surface goes to sea with its passive layer intact and no weld tint or embedded iron to start staining. Plain laser-cut parts with no welding are delivered with their protective film and clean cut edges.

Do you supply the material with certificates?

Yes. Stainless and aluminium sheet and plate come from our own stock with mill test certificates, heat numbers are transferred to cut parts on request, and duplex or alloy material outside the range we hold is sourced against the enquiry with its certificates. The article on 3.1 versus 3.2 certificates explains which level to ask for.