Are you confused about which stainless steel grades to choose? Let us help you! This article will explain the secrets of stainless steel specifications and help you make an easy purchase. Whether you are a home user who wants to upgrade your kitchenware or a construction professional looking for the ideal engineering material, we will compare the four common stainless steel grades: 201, 304, 316 and 430.

Chemical Composition

The four grades differ in key alloying elements: SS201 and SS304/316 are austenitic (high Ni, Mn, Cr), whereas SS430 is ferritic (no Ni). The table below summarizes the typical composition ranges (wt%) for chromium (Cr), nickel (Ni), molybdenum (Mo), and manganese (Mn):

SS201: Lower Ni (3.5–5.5%) than SS304, compensated by high Mn (5.5–7.5%).  This “chromium-manganese-nickel” alloy was developed to reduce Ni content.

SS304: The classic “18/8” austenitic grade with ~18–20% Cr and ~8–10.5% Ni.  Low carbon (≤0.08%) prevents carbide precipitation.

SS316: Similar Cr (16–18%) but higher Ni (10–14%) plus 2–3% Mo for improved corrosion resistance.  Carbon ≤0.08%.

SS430: A ferritic stainless steel with ~17% Cr and essentially no Ni.  Carbon up to 0.12%.  Lacks Mo; Mn is low (≤1%).

Corrosion Resistance

SS201: Offers fair corrosion resistance in mild (general) environments but is inferior to 304/316.  Its low Ni (∼1–5%) means it is prone to pitting/crevice corrosion under chloride attack.  It is suitable for indoor or light-duty applications (appliance trim, utensils) but is not recommended for marine or harsh acidic conditions.

SS304: Excellent all-around corrosion resistance in clean air, water, and many mild acids; widely used in food, kitchen, and architectural applications.  However, it can corrode in strong chlorides: it is susceptible to pitting and crevice corrosion in hot chloride solutions and can suffer stress-corrosion cracking above ~60 °C.  SS304 resists potable water up to ~200 ppm chloride (150 ppm at 60 °C).

SS316: By adding 2–3% Mo, SS316 has superior corrosion resistance in aggressive environments.  It is the “marine grade” stainless steel, resisting seawater and chloride acids much better than 304.  316 excels in chemical processing and saltwater applications.  (Note: even SS316 can show surface corrosion in warm seawater over time.)

SS430: Fair corrosion resistance in mild atmospheres and many oxidizing acids.  Its pitting/crevice resistance is roughly comparable to SS304 when well-polished.  430 resists nitric and organic acids well, but lacks Ni, so it performs poorly in acidic or chloride-rich conditions.  It is prone to rust in harsh environments and is not used where high corrosion resistance is needed (unlike 316 or 304).  On the plus side, all ferritic grades (including 430) resist stress-corrosion cracking excellently.

Mechanical Properties

The table below summarizes typical room-temperature mechanical properties for annealed material of each grade:

Key points: SS201 and SS304/316 (austenitic) have moderate tensile/yield and good ductility (long elongation). SS201 is comparatively strong (higher yield) but work-hardens quickly. SS430 (ferritic) has lower tensile and elongation (more brittle) but relatively higher yield strength. All grades are tough and can be formed or machined, though 430 has low ductility at room temperature.

Magnetic Properties

SS201, SS304, and SS316 are austenitic steels (face-centered cubic) and are non-magnetic in the annealed condition. In contrast, SS430 is ferritic (body-centered cubic) and is magnetic.  (Cold working can induce some magnetism in austenitics, but in practice, 201/304/316 do not attract magnets, whereas 430 does.)

Common Applications

Each grade finds use where its properties are best matched to the environment and cost:

SS201: Used in budget applications where moderate corrosion resistance is acceptable.  Common in cookware, kitchen utensils, and low-cost appliances (e.g., refrigerators, dishwashers) due to its affordability and formability. Also used for decorative trim, architectural accents, and automotive trim where high corrosion resistance is not critical.

SS304: The workhorse “18/8” stainless.  Ubiquitous in food and beverage, chemical, and architectural uses.  Applications include food processing equipment, kitchen sinks/countertops/appliances, dairy processing, pharmaceutical equipment, chemical containers, and piping.  It is also used in architectural panels, handrails, and automotive trim.  SS304 is widely specified for its hygiene and moderate corrosion resistance.

SS316: The marine and chemical-grade stainless.  Used wherever chloride corrosion or harsh chemicals are a concern.  Typical applications include marine hardware (boat fittings, seawater pumps), coastal architectural panels, chemical and petrochemical processing equipment, medical/surgical implants and instruments, heat exchangers, and high-quality kitchenware in saltwater areas.  (316L is used for heavy welded structures.)

SS430: Chosen where moderate corrosion resistance and magnetism are required at a low cost.  Common in home appliances: e.g. dishwasher linings, refrigerator cabinets, range hoods, stove trim, and chimney liners.  Also used in automotive trim and lashing wire, decorative trim, and electrical enclosures.  SS430F (free-machining variant) is used for machine screws and bolts.

Relative Cost

SS201: ~$1,000–1,800/ton (cheapest; low Ni).

SS430: ~$1,800–2,300/ton (no Ni, higher Cr; still inexpensive).

SS304: ~$2,500–3,200/ton (standard grade; moderate Ni).

SS316: ~$3,500–4,000/ton (high Ni + Mo; most expensive).

Thus，201 stainless steel and 430 stainless steel are relatively cheap, 304 stainless steel is moderately priced, and 316 stainless steel is the most expensive.

Advantages and Disadvantages

SS201:

Advantages: Very low cost and good formability/weldability. Relatively high strength and hardness.

Disadvantages: Lower corrosion resistance (especially in chloride environments) due to low Ni; not suitable for high-temperature service. Can be prone to welding cracks and work hardens rapidly.

SS304:

Advantages: Excellent general corrosion resistance and toughness; good formability and weldability; maintains strength at high temperatures (up to ~925 °C).

Disadvantages: Susceptible to localized corrosion (pitting/crevice) in warm chloride solutions; lower tensile strength than some grades. Not as corrosion-resistant as 316 in harsh environments (e.g., chlorides).

SS316:

Advantages: Superior corrosion resistance, especially against chlorides and acids (moisture, salt, chemicals); good high-temperature strength and formability similar to 304.316 stainless steel has good welding properties. It can be welded by all standard welding methods. Depending on the application, 316Cb, 316L or 309Cb stainless steel filler rods or welding rods can be used for welding. In order to obtain the best corrosion resistance, the welded section of 316 stainless steel needs to be annealed after welding.

Disadvantages: Higher material cost (Mo adds expense); slightly lower creep/rupture strength at very high temperatures; can still corrode in very aggressive hot seawater or acids over time.

SS430: 

Advantages: Low cost; good formability and mild corrosion resistance to many materials; magnetic (useful for certain applications); excellent resistance to stress-corrosion cracking and good polishability.

Disadvantages: Poor performance in strong corrosive or chloride environments (no Ni); limited suitability for high-temperature or welded components.  It work-hardens less, but has low ductility and is more difficult to weld than austenitic grades.

So，Each grade’s advantages must be weighed against its weaknesses: SS201 and SS430 save cost, SS304 offers balanced performance, and SS316 maximizes corrosion resistance.

Why does stainless steel also rust?

It is not uncommon for stainless steel to rust.When brown rust spots appear on the surface of stainless steel pipes, people are often surprised and mistakenly think that "real stainless steel will not rust, and rust must be a material problem or counterfeit." This is actually due to a one-sided misunderstanding of the characteristics of stainless steel. In fact, stainless steel will also rust under certain conditions.

Stainless steel has the ability to resist atmospheric oxidation (rust resistance) and the ability to resist corrosion by media such as acids, alkalis, and salts (corrosion resistance). However, its corrosion resistance is not absolute, but depends on the chemical composition of the steel itself, the processing state, the conditions of use, and the type of media in the environment. For example, 304 stainless steel pipes have excellent rust resistance in dry and clean air, but if they are in salt-rich fog on the seashore, rust spots will quickly appear; in contrast, 316 stainless steel pipes have better corrosion resistance in such environments. It can be seen that no stainless steel can remain completely rust-free and never corrode in all environments.