304 vs. 430 stainless steel: what’s the difference?
Stainless steels vary in their elemental and chemical composition. They share many of the same characteristics, but their individual properties set them apart from each other. We’ve put together this guide to help you understand not only how these two grades are similar, but also how they differ. We’ll cover:
What is 304 stainless steel?
Stainless steel grade 304 belongs to the austenitic stainless steels. It contains a minimum of 18% chromium and 8% – 10.5% nickel with a maximum of 0.08% carbon.
Chromium is the key element here – and it’s where stainless steel’s superior corrosion resistance comes from. The chromium forms a passive oxide layer on the surface of the steel, protecting it from rust and corrosion. The higher the chromium content, the greater the resistance to corrosion. Chromium also enhances the steel’s toughness and ductility, making it easy to work with. It’s also why 304 stainless steel stands up to high temperatures.
Nickel increases its resistance to corrosion, especially against acidic environments. The material's toughness and ductility is also helped by nickel, making it easier to form and fabricate. Carbon is added to improve the steel’s strength and hardness. However, if the carbon content is too high, it reduces the material's resistance to corrosion and makes it more difficult to weld.
304 stainless steel also contains small amounts of manganese, silicon, and sometimes molybdenum. These elements all contribute to the material's strength, formability, and weldability.
304 stainless steel is non-magnetic, which makes it useful in applications where magnetism is undesirable. This comes down to its austenitic microstructure, which is a face-centered cubic (FCC) crystal structure. The atoms in the lattice structure are symmetrically arranged, and their magnetic moments cancel each other out.
You can learn more about stainless steel in our guide:
Compare 304 stainless steel with other grades in our expert guides:
What is 304 stainless steel used for?
This corrosion-resistant metal is commonly used in these applications:
| Industry | Typical applications | Why |
|---|---|---|
| Food processing equipment | Tanks, pipes and containers | Resistance to corrosion, easy to clean |
| Consumer appliances | Sinks, refrigerators, dishwashers | Durability, resistance to corrosion, aesthetic appeal |
| Automotive | Exhaust systems, trim and grilles | Resistance to corrosion, aesthetic appeal |
| Medical equipment | Surgical instruments, dental instruments and implants | Biocompatibility, resistance to corrosion and withstands high-temperature cleaning processes |
| Chemical processing equipment | Reactors, tanks and pipelines | Resistance to corrosion, stands up to a range of chemicals |
| Aerospace components | Aircraft structures, engines | High strength-to-weight ratio, resistance to corrosion, thermal stability |
304 stainless steel is also used in small components. Examples include:
Spring-loaded removable concealed hinges
- 304 used for base materials, pins are 303
- 304 for MTH1 series
- Mesh is 304
Properties of 304 stainless steel
The characteristics of 304 stainless steel – as with any material – are a result of its properties. Let’s take a closer look:
What is 430 stainless steel?
430 stainless steel belongs to the ferritic stainless steel grades with 17% chromium. Grade 304 has slightly higher chromium content with a minimum of 18%.
Grade 430 also lacks nickel. This makes 430 stainless steel not as strong for corrosion and chemical resistance in harsh environments when compared to 304 stainless steel. Mind you, grade 430 still has very good corrosion resistance – it’s just not quite as high as 304 stainless steel. Also, be aware that the absence of nickel can make 430 stainless steel vulnerable to cracks during pressing.
430 stainless steel does have good thermal conductivity, which helps in applications where heat dissipation is important. It also has slightly higher heat resistance compared to 304 stainless steel.
Unlike 304 stainless steel, 430 is magnetic – hence, why it’s ideal for magnetic catches, as seen here. Like 304, 430 stainless steel also has good formability. However, ultimately 304 stainless steel has more versatility in its applications, hence why it's the most widely used of all stainless steels.
What is 430 stainless steel used for?
430 stainless steel costs far less than 304 stainless steel, which comes down to grade 430’s lack of nickel. While the price of metals constantly fluctuates, it’s not unusual to see grade 430 cost anywhere between 55% and 75% of 304 stainless steel.
Common applications for 430 stainless steel include the following:
| Industry | Typical application | Why |
|---|---|---|
| Automotive | Mufflers, trim | Corrosion resistance properties |
| Aircraft | Compressor blades | Corrosion resistance properties |
| Energy/power generation | Turbine engines | Corrosion resistant, maintains strength in heat |
| Consumer appliances | Refrigerator cabinet panels, range hoods, dishwasher linings | Cost effectiveness, easy to clean |
| HVACs | Heat exchangers, furnace parts | Thermal conductivity, Resistance to corrosion |
| Components | Fasteners/screws, Worm-drive hose clamp | Ease of fabrication, Resistance to corrosion |
Properties of 430 stainless steel
Both 304 and 430 have aesthetic appeal. Grade 430 has excellent finish properties, and coupled with its costs, it explains why it’s also used for decorative purposes, such as in elements of architecture and jewelry
A comparison of these stainless steel grades
It helps to see the composition of these different grades of stainless steel. As you can see, they're similar in many ways, but grade 304 has a higher nickel content which is one of the key differences.
| Element | 304 stainless steel % | 430 stainless steel % |
|---|---|---|
| Carbon | 0.07 | 0.08 |
| Chromium | 18.0 – 19.5 | 16 – 18 |
| Nickel | 8.0 – 10.5 | - |
| Silicon | 1.00 | 1.00 |
| Manganese | 2.00 | 1.00 |
| Phosphorous | 0.045 | 0.045 |
| Sulfur | 0.015 | 0.015 |
| Nitrogen | 0.10 | - |
Steel strength
Both of these steels have high strength. Grade 430 contains slightly more carbon, which means it should be stronger than 304. That said, the nickel in grade 304 contributes to its strength. Here’s how they’re mechanical properties compare – note, the ultimate tensile and tensile yield strengths measure the materials’ resilience to tensile (pulling) forces. The yield strength reflects the maximum stress before the material will deform permanently. The ultimate tensile strength describes maximum stress before fracture.
To understand the Rockwell B hardness test, see our guide, What’s shore hardness and why should you care?
| Properties | 304 stainless steel | 430 stainless steel |
|---|---|---|
| Ultimate Tensile Strength | 73,200 psi | 75,000 psi |
| Tensile Yield Strength | 31,200 psi | 50,000 psi |
| Hardness (Rockwell B) | 70 | 85 |
| Elongation at Break | 70% | 25% |
Properties of each steel
In summary, these are the primary characteristics of both steels. Both of these common grades have excellent corrosion resistance. Grade 430 has magnetic properties which is an important consideration for various industries. With their high formality they are durable for industrial applications.
| Characteristics | 304 stainless steel | 430 stainless steel |
|---|---|---|
| Corrosion resistance | Excellent | Very high |
| Magnetic | No | Yes |
| Weldability | High | Limited |
| Hardens during cold forming | Yes | No |
| Formability | Very good | Good |
| Machinability (annealed) | Fair | Good |
| Resistance to elevated temperatures | High | High |
| Maximum intermittent service temperature | 1562°F | 1562°F |
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