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Certifications & Compliences

Certifications & Compliance – Premium European Stainless Steel & Aluminium

OTK Stainless Steel B.V. supplies certified European stainless steel and aluminium with complete documentation, strict traceability, and guaranteed material integrity. Every coil, sheet and plate comes from audited mills operating under ISO-based quality systems, ensuring consistent performance, reliable processing, and full compliance with European and international standards.

Our customers rely on proper documentation for laser cutting, pressure equipment, food-grade production, marine structures, deep drawing, roll-forming, tanks and welding applications.
Because of that, we deliver materials only from mills and service centres that meet the highest certification requirements in the industry.

Why Certified Materials Matter — and Why Clients Choose OTK

Choosing certified material ensures:

  • Verified chemical composition of every heat
  • Consistent mechanical properties (tensile, yield, elongation)
  • Dimensional and surface tolerances according to EN / ASTM
  • Full batch traceability from melting to final processing
  • Safety compliance for pressure vessels, boilers and technical installations
  • Approved use in marine, offshore and high-corrosion environments
  • Guaranteed European origin, no mixed sources or incorrect documents
  • Documentation suitable for audits, inspections and industrial quality systems

Our certifications allow your production to meet CE, ISO, and EU compliance requirements, minimizing risk and ensuring smooth approval for your end products.

Stainless Steel Certifications & Quality Control

All stainless steel supplied by OTK complies with the following standards and documentation requirements:

✔ EN 10088 — Grades, Chemistry & Mechanical Values

Defines stainless steel grades, chemical composition, tensile strength, yield strength, elongation and hardness.

✔ EN ISO 9445 — Tolerances for Cold-Rolled Strip

Ensures precision thickness, width and flatness — crucial for slitting, roll-forming, tube production and stamping.

✔ EN 10204 — 3.1 Certification Included

Every delivery includes 3.1 certificates verifying:

  • Chemical analysis
  • Mechanical test results
  • Heat number and product traceability
  • Surface finish compliance

✔ ASTM A240 / A480 (On Request)

For customers working under American specifications, we provide ASTM-compliant stainless steel when required.

✔ Optional 3.2 Inspection

Issued by independent authorities such as:

  • TÜV
  • SGS
  • Bureau Veritas (BV)

Used for high-risk or critical applications, offshore structures, boilers and pressure vessels.

Marine & Offshore Certifications

For maritime and offshore end users, we supply stainless steel meeting the requirements of:

  • DNV
  • ABS
  • Lloyd’s Register (LR)
  • Bureau Veritas (BV)
  • RINA

These approvals are essential for:

  • Saltwater-exposed fabrication
  • Marine equipment
  • Offshore platforms
  • Structural components
  • High-corrosion environments

Materials can be delivered with appropriate classification society documentation on request.

PED — Pressure Equipment Directive (2014/68/EU)

OTK supplies stainless steel fully compliant with PED Annex I, suitable for:

  • Boilers
  • Pressure vessels
  • Heat exchangers
  • Certified piping systems
  • High-pressure installations

PED-compliant material includes:

  • 3.1 or 3.2 certificates
  • Verified EN-compliant chemistry
  • Verified mechanical values
  • Optional UT / PT / RT testing
  • Mill approval according to PED Annex I, Section 4.3

Mechanical & Surface Quality Testing

Each batch is tested and verified for:

  • Chemical analysis
  • Tensile strength, yield strength, elongation
  • Surface finish compliance (2B, BA, No.1, 2D, SB, brushed)
  • Thickness, width and flatness tolerances
  • Optional corrosion tests (pitting, salt spray, intergranular)

This ensures a stable and predictable performance in production, even for deep drawing, bending, cold forming and precision laser cutting.

Aluminium Certifications & Quality Compliance

Our aluminium coils and sheets come from audited European mills with strict quality systems. Every shipment includes:

  • Full traceability
  • Verified mechanical properties
  • Verified chemical composition
  • EN-compliant tolerances
  • 3.1 certification

Applicable Standards

  • EN 485 — Tolerances & mechanical properties
  • EN 573 — Chemical composition
  • EN 546 — Aluminium foil specifications
  • EN 10204 3.1 — Certified documentation
  • Optional 3.2 inspection for critical applications

Marine & Offshore Aluminium Compliance

Aluminium grades (especially 5005, 5052, 5083, 5754, 6082) can be supplied with approvals from:

  • DNV
  • ABS
  • LR
  • BV
  • RINA

Suitable for:

  • Shipbuilding
  • Aluminium superstructures
  • Tanks and hydraulic systems
  • Offshore fabrication
  • Salt-water exposed components

PED for Aluminium (Pressure Equipment)

Aluminium products can be delivered PED-compliant with:

  • 3.1 / 3.2 certificates
  • Verified mechanical & chemical values
  • Optional corrosion, tensile and hardness testing
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