Stainless Steel 430: Properties, Composition, and Applications
Dec 08, 2025
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What Is Stainless Steel 430?
Stainless steel 430 is a ferritic grade containing approximately 16 to 18 percent chromium and very little nickel. Its body-centred cubic crystal structure makes it magnetic and gives it a lower coefficient of thermal expansion than austenitic grades such as 304. Because it contains almost no nickel, it is normally less expensive than 304 and 316 while still providing useful corrosion resistance in dry indoor and mildly corrosive service. It is produced as sheet, strip, plate, bar and wire, with plate and sheet requirements defined in ASTM A240, EN 10088 and JIS G4304/G4305, and Chinese equivalent GB/T 3280.
Chemical Composition
The table below lists composition requirements for 430 plate and sheet across the three main standards. Chromium provides the protective passive film; carbon is controlled to limit chromium-carbide precipitation during welding.
| Element | ASTM A240 S43000 | EN 1.4016 X6Cr17 | JIS SUS430 |
|---|---|---|---|
| Carbon, max | 0.12 | 0.08 | 0.12 |
| Manganese, max | 1.00 | 1.00 | 1.00 |
| Phosphorus, max | 0.040 | 0.040 | 0.040 |
| Sulfur, max | 0.030 | 0.030 | 0.030 |
| Silicon, max | 1.00 | 1.00 | 0.75 |
| Chromium | 16.00-18.00 | 16.0-18.0 | 16.00-18.00 |
| Nickel, max | 0.75 | - | 0.60 |
| Nitrogen, max | 0.10 | - | - |
Mechanical Properties
In the annealed condition, 430 plate and sheet meet the minimum values below, consistent with ASTM A240. Density is about 7.75 g/cm3 and the melting range is approximately 1430 to 1510 degrees C. The grade retains useful strength to about 815 degrees C in continuous service, but oxidation resistance falls rapidly above that range.
| Property | Minimum Value |
|---|---|
| Tensile strength | 450 MPa |
| Yield strength, 0.2 percent offset | 205 MPa |
| Elongation in 50 mm | 20 percent |
| Hardness, max | 183 HBW |
Corrosion Resistance and Limitations
430 performs well in atmospheric exposure, fresh water, food-processing environments and mildly oxidising media, because the passive chromium oxide film remains stable under oxidising conditions. It is, however, far less resistant than molybdenum-bearing grades to pitting and crevice corrosion in chloride environments, and it is attacked by reducing acids such as hydrochloric acid and by dilute sulfuric acid at elevated temperature. For coastal railings, marine fittings or swimming-pool environments, 316 or 316L is the appropriate choice; 430 should be limited to indoor, dry or sheltered applications where its cost advantage and magnetism are useful.
Fabrication and Applications
430 can be formed by bending, deep drawing and roll forming. It work-hardens less rapidly than austenitic grades, but its higher yield-to-tensile ratio must be allowed for in tooling design. Welding is possible with conventional processes, although the heat-affected zone can suffer grain growth and loss of ductility, and the grade is susceptible to sensitisation in the range of about 425 to 600 degrees C. Low heat input, matched filler metal and rapid cooling are recommended; where weld toughness is critical, an austenitic filler such as ER308L is often selected. Available finishes include 2B, BA and No.4, and the material polishes and cleans readily. Typical applications include kitchen equipment, sinks, cookware and dishwasher liners; washing-machine drums and appliance components; indoor architectural panels and elevator cladding; automotive trim; and fasteners, brackets and general hardware where 304 is not required.
Frequently Asked Questions
Q: Is 430 stainless steel magnetic? Yes. The ferritic structure is body-centred cubic and ferromagnetic, so magnets will stick to 430, unlike annealed 304 or 316.
Q: Can 430 be hardened by heat treatment? No. Ferritic grades cannot be hardened by quenching; strength can be increased only by cold working.
Q: Where should 430 not be used? Avoid chloride-rich coastal or marine service, swimming pools, road-salt exposure and reducing acids, where pitting or general corrosion can occur.
Q: What is the difference between 430 and 304? 304 is an austenitic grade with about 18 percent chromium and 8 percent nickel, is essentially non-magnetic and resists a wider range of media. 430 offers lower cost and magnetism but lower corrosion resistance.
Q: Can 430 be welded without problems? It can be welded, but the heat-affected zone is prone to grain growth and sensitisation. Use low heat input and a suitable filler, and avoid service conditions demanding maximum toughness.
Q: Which standards govern 430? ASTM A240 for plate and sheet, ASTM A276 for bar, EN 10088 for European equivalents, JIS G4304/G4305 for Japanese equivalents, and GB/T 3280 for Chinese plate and sheet.
Frequently Asked Questions
Q1. What is the composition of 430 per ASTM A240?
Carbon 0.12 max, manganese 1.00 max, silicon 1.00 max, chromium 16.00-18.00 and nickel 0.75 max; the EN 1.4016 (X6Cr17) designation limits carbon to 0.08 max.
Q2. What are the annealed mechanical properties of 430?
Tensile strength 450 MPa min, yield strength 205 MPa min, elongation 20 percent and hardness 183 HBW max.
Q3. What is the temperature limit of 430?
It retains useful strength to about 815 degrees C in continuous service, but oxidation resistance falls rapidly above that range.
Q4. Which finishes are available on 430?
2B, BA and No. 4; the material polishes and cleans readily.
Q5. Why does 430 cost less than 304?
It contains very little nickel (0.75 max), and its body-centred cubic structure makes it magnetic with a lower coefficient of thermal expansion than austenitic grades such as 304.
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