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Industry procurement solution · Reviewed 31 July 2026

Metals for Shipbuilding

Ship metal selection follows vessel class, flag and class rules, structural zone, seawater exposure, cargo, temperature, welding procedure, fire safety, and inspection—not a universal marine-grade list.

01 Service environment02 System requirements03 Codes & documents04 Inspection & delivery

Answer first

There is no single metal specification for an entire project

Divide the project into systems, document each service environment and governing code, then select compatible materials, product standards, fabrication routes, protection systems and inspection plans.

01Service environment

Immersed, splash, weather-deck, ballast, cargo, and machinery-space exposure

02Service environment

Cyclic wave loading, vibration, fatigue, impact, low temperature, and welding restraint

03Service environment

Seawater chlorides, cargo chemistry, exhaust heat, condensation, and cleaning chemicals

System map

Material and product selection by project system

SystemSelection drivers and alternativesReviewed starting points
Hull and deck structure
  • Use class-approved shipbuilding grades with required toughness, thickness, delivery condition, and traceability.
  • Plate acceptance and welding follow the classification society rules and approved vessel design.
Carbon steel plateCarbon and structural steel
Piping and seawater systems
  • Define fluid, pressure, temperature, velocity, chloride level, stagnant zones, and galvanic interfaces.
  • Pipe, fittings, welding consumables, NDE, and pressure tests require a common class-approved specification.
Stainless pipeCopper alloys
Cargo, service, and ballast tanks
  • Select material and coating around cargo compatibility, cleaning, access, drainage, and inspection.
  • Stainless selection requires chloride and stress-corrosion assessment; carbon steel requires a complete coating and corrosion-control plan.
316LCarbon steel plate
Exhaust and high-temperature zones
  • Confirm operating and transient temperatures, condensate chemistry, cyclic oxidation, and support loads.
  • High-temperature grade selection remains subject to the exhaust-system design and product standard.
321347
Accommodation, electrical, and outfitting
  • Coordinate fire safety, weight, finish, electrical continuity, condensation, and cleaning.
  • Aluminum and coated products require isolation from dissimilar metals in wet zones.
Aluminum sheet & plateGalvanized coil

Project control

Standards, certification and documents

  • Applicable classification society rules and IACS Unified Requirements
  • SOLAS, flag-state, and vessel-specific fire and safety requirements
  • Approved material list, welding procedures, welder qualifications, and NDE plan
  • Coating technical file, corrosion-control drawings, and cathodic-protection interfaces
  • Class certificates, mill test reports, traceability, and construction records

Fabrication and logistics

Package interfaces to control

  • Fabrication drawings, welding, heat treatment, coating and repair procedures
  • Inspection hold points, testing methods, acceptance criteria and document approval
  • Identification through cutting and assembly, preservation, packing and consolidated shipping
  • Destination rules, site storage, installation interfaces and delivery sequence

Risk register

Common procurement risks

01

Buying nominally similar plate without class approval, toughness, thickness, or delivery-condition compliance

02

Galvanic couples and crevices created by mixed metals, fasteners, insulation, or trapped seawater

03

Incomplete weld, NDE, coating, or class witness requirements at purchase-order stage

04

Loss of heat and plate traceability during nesting, cutting, fabrication, or consolidation

Comparable offers

Structured RFQ checklist

01RFQ input

Project location, service environment, design life, and governing codes

02RFQ input

System or component, material grade, and governing product specification

03RFQ input

Dimensions, tolerance, quantity, and delivery lot sequence

04RFQ input

Condition, finish, coating, corrosion allowance, or cathodic-protection interface

05RFQ input

Welding procedure, fabrication, heat treatment, and qualification requirements

06RFQ input

Inspection and test plan, acceptance criteria, certificates, and third-party hold points

07RFQ input

Marking, traceability, packing, preservation, and destination

08RFQ input

Required delivery date, shipment terms, and approved-vendor constraints

Continue researching

materialCarbon & Structural Steel

Carbon and structural steels cover high-volume engineering materials supplied under chemistry-, strength-, product-, and application-based specifications. A familiar grade name never replaces the governing product standard and delivery condition.

materialStainless Steel

Stainless steels are iron-based alloys whose chromium supports a protective passive film. Family, alloy content, product specification, condition, fabrication, surface state, and service environment all affect selection.

materialAluminum & Aluminum Alloys

Aluminum alloys combine low density with corrosion resistance, conductivity, formability, and a broad range of strength. Alloy series, product form, temper, thickness, joining route, and exposure must be specified together.

productStainless Steel Pipe

A specification guide to seamless and welded stainless pipe for pressure and process service, with schedule, dimensions, heat treatment, testing, and end requirements.

Evidence

Sources and review

Project engineering documents and current governing standards supersede this general selection map.

01
International Convention for the Safety of Life at Sea — Ship Construction

International Maritime Organization · SOLAS chapters II-1 and II-2 overview, reviewed July 2026

02
Unified Requirements

International Association of Classification Societies · Current technical requirements index, reviewed July 2026

03
The Stainless Steel Family

worldstainless · Industry technical guide, reviewed July 2026

Project sourcing from China

Build a traceable Shipbuilding supply package

Share the design basis, system list, specifications, quantities, inspection plan, destination and delivery schedule.

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