Stainless Steel - Ferritic - 1.4003 Specification

Stainless Steel - Ferritic - 1.4003 Specification

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1.4003 Sheet and Plate

Type 1.4003 stainless steel is a utility ferritic stainless steel, often used in place of mild steel. It offers the benefits of more highly alloyed stainless steels such as strength, corrosion and abrasion resistance, durability and low maintenance. In addition type 1.4003 Is weldable and formable allowing it to be fabricated using conventional techniques.

Families of ferritic stainless steels. Image credit:

Benefits of using type 1.4003 stainless steel: 

~ 250 times greater corrosion resistance than mild steel
~ Corrosion/abrasion resistance
~ Economical - Low initial cost, low maintenance
~ High Strength
~ Excellent impact resistance
~ Can be welded by conventional methods
~ Can eliminate need for protective coating
~ Can eliminate need for corrosion allowance
~ Proven success in many applications across a wide range of industries
~ Good performance at elevated temperatures
~ Lower cost than austenitic stainless

This has led to the use of type 4003 stainless steel in many applications across a broad range of industries.

Chemical Composition

  • Chemical Element % Present
  • Carbon (C) 0.0 - 0.03
  • Chromium (Cr) 10.50 - 12.50
  • Manganese (Mn) 0.0 - 1.50
  • Silicon (Si) 0.0 - 1.00
  • Phosphorous (P) 0.0 - 0.04
  • Sulphur (S) 0.0 - 0.02
  • Nickel (Ni) 0.30 - 1.00
  • Nitrogen (N) 0.0 - 0.03
  • Iron (Fe) Balance

Stainless steel – do you know your ferritic from your austenitic


  • Physical Property Value
  • Density 7.74 g/cm³
  • Melting Point 1430-1510 °C
  • Thermal Expansion 11.1-12.3 x10^-6 /K
  • Modulus of Elasticity 200 GPa
  • Thermal Conductivity 30.5 W/m.K
  • Electrical Resistivity 0.0678 x10^-6 Ω .m
  • Mechanical Property Value
  • Proof Stress 250 Min MPa
  • Tensile Strength 450-650 MPa
  • Elongation A50 mm 18 Min %
  • Compressive Strength 280 Min MPa
  • Properties listed above are for 1.4003 Sheet / Plate

Alloy Designations

Stainless Steel Grade 1.4003 also corresponds to but may not be a direct equvalent to:

  • 3CR12
  • Nirosta 4003 

Supplied Forms

  • Sheet
  • Tube
  • Plate
  • Applications

1.4003 stainless steel is typically used in:

  • Bulk wet materials handling
  • Vehicle frames/chassis
  • Rail car hoppers
  • Sweeper and gritter vehicles
  • Conveyors, chutes, screen, troughs
  • Bunkers & hoppers
  • Tanks & containers
  • Chimneys & ducting
  • Enclosures & cabinets
  • Walkways, stairs & railings
  • Cable trays

Corrosion Resistance

!.4003 stainess has 250 times the corrosion resistance of mild steels  and is particularly good in corrosion/abrasion applications.

Corrosion/Abrasion - The cycle of abrasive removal of a metal surface following surface corrosion rapidly erodes mild/carbon steels even when costly coatings are applied.  In wet or damp conditions where abrasion is present type 4003 provides excellent performance by resisting corrosion attack and thus maintaining better flow and slideability  compared to non-alloyed or low-alloy steels including abrasion resistant grades.


Type 4003 has a fine-grained microstructure which reduces grain growth in the heat-affected zone (HAZ) and allow high integrity welds in section thicknesses up to 30mm.  Suitable weld processes include SMAW, GTAW, FCAW, PAW, Laser, Spot and Seam.  Design and welding procedure consideration must be taken to avoid sensitization occurring in service.

Strength & Stiffness

Type 4003 offers higher strength than, and equal structural stiffness to, mild steels such as BSEN10113 Grade Fe430A (ASTM A36).  It also offers greater impact and energy resistance than aluminium.  It behaves much like austenitic steel in that it gradually yields and does not show a definite yield point.

Coating & Painting

Type 4003 provides good corrosion resistance and excellent abrasion resistance, hence does not need coating or painting systems to be applied for performance reasons.  For aesthetic reasons it may be desirable in some applications to apply paint, especially as type 4003 will tend to discolour in corrosive conditions.  Type 4003 has exceptional under-paint corrosion resistance and will continue to resist corrosion even where the paint coat has been damaged.  Normal preparation is required, such as ensuring a clean surface free of grease and other contamination.  A primer coat is recommended for cold-rolled material due to its smoother surface, but hot rolled 1D finish material may be suitably painted in a single coat.

Cost Benefit

Type 4003 is proven to offer lower life-cycle costs than traditional materials where service conditions involve corrosion and/or abrasion.  As compared to traditional materials there are options to reduce initial cost through the elimination of protective coatings and corrosion allowances.  In service cost savings come from reduced maintenance, improved productivity and significantly longer life.

As type 4003 does not contain significant quantities of expensive alloying elements such as Nickel and Molybdenum, it is a lower cost material than austenitic stainless steel and can thus be considered as an option where these grades are not an economically viable choice.



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