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Materials/Metals and alloys/Stainless steels

Ferritic stainless steels

stainless-ferritic

4 materials across 1 types

About ferritic stainless steels

Ferritic stainless steels (430): composition, strength and corrosion data with sources.

Ferritic stainless steels are chromium steels with a body-centred cubic structure. They are magnetic and are not hardened by heat treatment.

At a glance

  • Highest yield strength: Stainless steel 430F reaches 500 MPa. Lowest: Stainless steel 409 starts at 170 MPa. (4 of 4 grades have a sourced value.)
  • Highest tensile strength: Stainless steel 430F reaches 850 MPa. Lowest: Stainless steel 409 starts at 380 MPa. (4 of 4 grades have a sourced value.)

Ranges run across the conditions each source reports (temper, heat treatment, form), measured at room temperature where the source says so.

How they compare

The same measurements for every material in the collection. A range means the grade has values under several conditions; "at least" means the source gives a specified minimum. "no data" means no sourced value yet. For ranked tables, open a benchmark.

Ferritic stainless steels: how the grades compare
MaterialYield strengthTensile strengthDensityYoung's modulusThermal conductivityMelting point
Stainless steel 430corrosion-resistant trim and sheet alloy 207 to 386 MPa400 to 630 MPa7.7 to 7.74 g/cm³200 GPa23.9 to 26 W/(m·K)1,425 to 1,510 °C
Stainless steel 409exhaust and muffler stainless steel 170 to 255 MPa380 to 560 MPa7.6 to 7.75 g/cm³208 to 220 GPa25 to 25.8 W/(m·K)no data
Stainless steel 444corrosion-resistant ferritic sheet, tube and tank alloy 275 to 350 MPa415 to 600 MPa7.7 to 7.75 g/cm³215 to 220 GPa23 W/(m·K)no data
Stainless steel 430Ffree-machining bar alloy for automatic screw machines 379 to 500 MPa552 to 850 MPa7.7 g/cm³200 GPa25 W/(m·K)1,482 °C

What these materials are made of

Composition by weight, as printed in the sources for each grade (the first constituents listed).

Composition of each grade
MaterialMain constituents
Stainless steel 430Fe balance · Cr 16 to 18% · C up to 0.12% · Mn up to 1% · Si up to 1% · Ni up to 0.75% · P up to 0.04%
Stainless steel 409Fe balance · Cr 10.5 to 11.8% · Ti up to 0.75% · C up to 0.08% · N up to 0.03% · Mn up to 1% · Si up to 1%
Stainless steel 444Fe balance · Cr 17.5 to 19.5% · Mo 1.75 to 2.5% · C up to 0.025% · N up to 0.035% · Si up to 1% · Mn up to 1%
Stainless steel 430FFe balance · Cr 16 to 18% · S 0.15 to 0.35% · C up to 0.12% · Mn up to 1.25% · Si up to 1% · P up to 0.06%

Where they are used

Uses
UseGrades
Architectural trim, industrial roofing and wall claddingStainless steel 430
Sinks, sink rims, range hoods, dishwashers and appliance trimStainless steel 430
Automotive trim and appliance componentsStainless steel 430
Automotive exhaust systems, mufflers and pipesStainless steel 409
Exhaust manifolds, down-pipes, converter casings and mufflersStainless steel 409
Heat exchangersStainless steel 409
Heat exchanger tubing, boilers and hot water tanksStainless steel 444
Photovoltaic frames and solar panelsStainless steel 444
Automotive exhaust systemsStainless steel 444
Machined parts cut from 430F bar on automatic screw machinesStainless steel 430F
Electronic equipmentStainless steel 430F
Automotive industry componentsStainless steel 430F

When each grade fits

Best use and weak spots of each grade
MaterialBest forWeakest at
Stainless steel 430Sinks, appliance trim and architectural cladding, where economy and moderate corrosion resistance matter more than strength (ATI)Welds and sea water. Welds lose ductility and corrosion resistance, and the datasheet says the grade is not resistant to sea water (Deutsche Edelstahlwerke)
Stainless steel 409Automotive exhaust systems and heat exchangers, where corrosion protection is needed beyond carbon steel (Combined Metals)Pitting and intergranular corrosion: Outokumpu prints a critical pitting temperature below 10 °C and N/N for intergranular corrosion, and Aalco limits welded sheet to about 2.5 mm thick
Stainless steel 444Hot water tanks, heat exchangers and solar tanks in chloride-bearing water, where resistance to chloride stress cracking matters (ATI, Ugitech, Aperam)Boiling 10 percent sulphuric and sulfamic acids, where ATI's table shows corrosion above 1000 mils per year, and toughness at transition temperatures, welds included (Aperam)
Stainless steel 430FMachined parts cut from bar on automatic screw machines, where machinability matters more than corrosion resistance or weldability (Atlas, Deutsche Edelstahlwerke)Corrosion and welding. The sulphur addition reduces corrosion resistance, especially pitting and crevice attack, and weldability is poor (Deutsche Edelstahlwerke)