When choosing stainless steel for automotive exhausts, kitchen equipment, appliances, or industrial components, 439 stainless steel and 304 stainless steel are two of the most commonly compared materials. Although both offer corrosion resistance and durability, they are designed for different environments and cost expectations.
What is 439 stainless steel?
AISI 439 is a ferritic stainless steel containing 17-19% chromium and stabilized with titanium. It exhibits excellent resistance to high-temperature oxidation, a low coefficient of thermal expansion, and superior resistance to stress corrosion cracking compared to 304 stainless steel in chloride environments. Because it contains no nickel, its cost is lower than 304 stainless steel. It is used in exhaust systems, heat exchangers, household appliances, and welded components.
What is 304 stainless steel?
AISI 304 is an austenitic stainless steel containing 18% chromium and 8% nickel. It is the most widely used stainless steel grade globally, possessing good formability and weldability, and higher toughness across the entire temperature range. Due to its nickel content, it is more expensive and widely used in food processing, chemical equipment, building decoration, piping, and ship components.
439 vs 304: Chemical Composition Comparison
| Grade | Cr (%) | Ni (%) | C (%) | Ti (%) | Structure |
|---|---|---|---|---|---|
| 439 | 17.0–19.0 | ≤0.50 | ≤0.03 | Added | Ferritic |
| 304 | 18.0–20.0 | 8.0–10.5 | ≤0.08 | - | Austenitic |
439 vs 304 stainless steel :Mechanical Properties
| Property | 439 | 304 |
|---|---|---|
| Tensile Strength (MPa) | 380–450 | 515–750 |
| Yield Strength (MPa) | 170–260 | 205–300 |
| Elongation (%) | 20–25 | 40 |
| Hardness (HB) | ≤200 | ≤201 |
439 vs 304 Stainless Steel: Corrosion Resistance
439 and 304 stainless steels have comparable corrosion resistance, but 304 is generally more popular due to its more comprehensive corrosion resistance, especially in general environments. 439 stainless steel has corrosion resistance close to 304 and performs well in specific environments such as pitting and crevice corrosion in chloride environments. The main difference is that 304 is an austenitic stainless steel, non-magnetic, and has very stable corrosion resistance, while 439 is a ferritic stainless steel, magnetic, and has lower elongation.
439 vs 304 Stainless Steel: Heat Resistance
439 stainless steel has lower heat resistance than 304 stainless steel, especially in high-temperature and corrosive environments. 304 stainless steel is an austenitic stainless steel with good high-temperature resistance, generally with a service temperature limit of up to 650°C. 439 stainless steel is a ferritic stainless steel with good thermal conductivity and mechanical properties, suitable for building decoration, appliance components, and fuel burners, etc.
Is 439 magnetic?
Yes, stainless steel grade 439 is magnetic. It is a type of ferritic stainless steel, which contains a high amount of iron and has a crystal structure that makes it magnetic.
Application Comparison
| Application Field | 439 | 304 |
|---|---|---|
| Exhaust Pipes | ✔ Excellent | ✔ Good |
| Kitchen Equipment | ✔ Good | ✔ Excellent |
| Chemical Processing | ✘ Not recommended | ✔ Excellent |
| Marine Use | ✘ Poor chloride resistance | ✔ Good |
| Home Appliances | ✔ Low cost | ✔ High-end |
| Tanks/Pipes | ✔ Only for mild media | ✔ Wide range |
439 stainless steel vs 304: Price Difference (Latest Market Trend)
439 stainless steel sheet price: USD 900–1,200 / ton
304 stainless steel sheet price: USD 1,400–1,750 / ton
GNEE currently offers a stock of SUS 439 stainless steel products, including: plates, sheets, coils, strips, tubes, bars, and wires. In addition, we provide a variety of surface treatments for your selection, such as: No. 1, 2B, 2D, BA, No. 3, No. 4, HL, No. 8, and sandblasting.
We guarantee 100% quality. We will never deliver any defective products to our customers. Please contact us to customize your product specifications, including shape, condition, surface treatment, and processing technology.
