Forta H400
EN 1.4376

General characteristics

Forta H400 has higher strength than standard Core 304/4301 and a lower nickel content, making it a cost-effective and lightweight austenitic product for the automotive industry. It has been used in automotive applications for over 10 years.

Forta H400 is an austenitic stainless steel, which belongs to the austenitic low-nickel CrMn stainless steel family, in which manganese replaces part of the nickel that is normally alloyed to CrNi standard grades. This variant has low carbon content. Due to its high nitrogen content, Forta H400 has increased mechanical strength. Forta H400 is optimized for strong work hardening on mechanical deformation.

The corrosion resistance of the austenitic CrMn grades is usually slightly below that of the austenitic CrNi standard grades. Forta H400 is used in applications where a combination of high mechanical strength and good formability, as well as corrosion resistance, is needed. Due to its strong tendency to work hardening, Forta H400 can absorb a high amount of energy during deformation. It can be delivered in the temper rolled condition with different strength levels.


Typical applications

  • Cross members
  • Strut domes
  • Bumpers


Product forms, available sizes and finishes


Product typeFinishesThicknessWidth
Cold rolled coil and sheet2B1,50-4,00≤ 1500
Hot rolled coil and plateHot rolled white3,00-6,00≤ 1500
Chemical composition


The typical chemical composition for this grade is given in the table below, together with composition limits given for the product according to different standards. The required standard will be fully met as specified on the order.

The chemical composition is given as % by mass.

TypicalForta H4000.046.817.54.00.20
EN 10088-21.4376<0.105.0-8.017.0-20.52-4.5<0.30Si:<1 P:<0.045 S:<0.015
Mechanical properties



StandardGradeRp0.2Rp1.0RmImpact strengthRockwellHBHV
Product type: Cold rolled coil and sheet
Typical (thickness 1 mm)Forta H40040545574090HRB
Product type: Hot rolled coil and sheet
Typical (thickness 4 mm)Forta H40041046071586

1)Elongation according to EN standard:
A80 for thickness below 3 mm.
A for thickness = 3 mm.
Elongation according to ASTM standard A2” or A50.

Corrosion resistance

Forta H400 has excellent corrosion resistance in solutions of many halogen-free organic and inorganic compounds over a wide temperature and concentration range. It can withstand many organic and sufficiently diluted mineral acids depending on the temperature of the solution. Forta H400 may suffer from uniform corrosion in mineral acids and hot strong alkaline solutions.

In aqueous solutions containing halogenides, e.g. chlorides or bromides, pitting and crevice corrosion may occur depending on halogenide concentration, temperature, pH-value, concentration of oxidizing compounds, or crevice geometry, if applicable. The resistance against pitting and crevice corrosion of Forta H400 is, however, slightly lower than of the basic austenitic CrNi standard grades. The presence of corrosion-inhibiting or accelerating compounds like transition metal ions or organic compounds may influence the corrosion behavior of Forta H400.

Forta H400 is prone to chloride-induced stress corrosion cracking at temperatures over about 50 °C depending on the applied stress and the chloride concentration in the environment. Prior cold deformation of the structure under load increases the risk of stress corrosion cracking.

Forta H400 can be used for indoor and outdoor applications in rural areas and urban environments where chloride contamination is low. The best material performance is reached usually with the help of adequate design, correct post-weld treatment, and regular cleaning during use (if applicable).

For more information on corrosion resistance, please refer to the Outokumpu Corrosion Handbook or contact our corrosion experts.

Pitting corrosion resistanceCrevice corrosion resistance

PRE Pitting Resistant Equivalent calculated using the formula: PRE = %Cr + 3.3 x %Mo + 16 x %N
CPT Corrosion Pitting Temperature as measured in the Avesta Cell (ASTM G 150), in a 1M NaCl solution (35,000 ppm or mg/l chloride ions).
CCT Critical Crevice Corrosion Temperature is the critical crevice corrosion temperature which is obtained by laboratory tests according to ASTM G 48 Method F



Physical properties



DensityModulus of elasticityThermal exp. at 100 °CThermal conductivityThermal capacityElectrical resistanceMagnetizable

*) Austenitic stainless steel grades may be magnetizable to a certain degree after cold deformation, e.g. in temper rolled condition.



More detailed information concerning welding procedures can be obtained from the Outokumpu Welding Handbook, available from our sales offices.

Standards & approvals



EN 10088-21.4376