What is 18/8 Stainless Steel? Composition, Properties & Uses
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What is 18/8 Stainless Steel?
18/8 stainless steel refers to stainless steel containing 18% chromium and 8% nickel. In most commercial applications, 18/8 stainless steel is equivalent to AISI 304 stainless steel-the most widely used austenitic stainless steel globally. However, it is also known by three other designations: 06Cr19Ni10, 304, and SUS304. Specifically, 06Cr19Ni10 typically denotes production according to Chinese national standards, 304 indicates compliance with US ASTM standards, and SUS304 signifies adherence to Japanese standards.
18/8 stainless steel has become the material of choice for food processing equipment, kitchenware, architectural components, medical equipment, industrial piping, and chemical processing systems.
What Does 18/8 Mean?
The designation "18/8" simply indicates the approximate percentage of two primary alloying elements:
| Element | Content | Function |
|---|---|---|
| Chromium (Cr) | About 18% | Corrosion resistance and oxidation resistance |
| Nickel (Ni) | About 8% | Toughness, ductility, formability, weldability |
Key Advantages of 18/8 Stainless Steel
Corrosion Resistance：The 18% chromium content forms a self-healing chromium oxide layer that protects the surface against moisture, oxidation, and many mild chemicals.
This makes 18/8 stainless steel suitable for: Food processing,Beverage production,Pharmaceutical equipment,Commercial kitchens,Water treatment systems.
Durability and Heat Resistance: The addition of nickel enhances the metal's ductility and strength. It withstands extreme temperatures up to 870°C (1600°F) without performance degradation, making it ideal for manufacturing cookware and automotive components.
Food-Grade Safety: As the material does not leach harmful chemicals or react with acidic or alkaline foods, it fully complies with FDA and NSF standards, serving as an industry benchmark for commercial kitchens, breweries, and food processing equipment.
Excellent Formability: 304 stainless steel possesses exceptional ductility, allowing for easy deep drawing, spinning, or rolling into complex shapes without cracking.
Cost: Compared to premium marine-grade alloys like 316, the 18-8 alloy is 20% to 40% less expensive, yet it significantly outperforms 400-series alloys (which contain only chromium).
SS 304 vs. SUS304 Material ：Chemical Composition
|
Steel Grade |
SUS304 |
SS 304 |
|
C ≤ |
0.08 |
0.07 |
|
Si ≤ |
1.00 |
0.75 |
|
Mn ≤ |
2.00 |
2.00 |
|
P ≤ |
0.045 |
0.045 |
|
S ≤ |
0.030 |
0.03 |
|
Cr |
18.00-20.00 |
18.0-20.0 |
|
Ni |
8.00-10.50 |
8.0-10.5 |
SS 304 vs. SUS304 Material ：Physical Properties
|
Density(g/cm3) |
Melting point (℃) |
Specific heat (J/kg·℃) |
Electrical resistivity (μΩ·m) (20℃) |
Thermal expansion (10-6/K) |
Thermal conductivity (W/m·K) |
|
|
SUS304 Material |
7.93 |
1,400-1,450 |
460-502 |
0.73 |
16.3 (20-100℃) 17.8 (20-300℃) 18.4 (20-500℃) |
16.8 (100℃) |
|
SS 304 Material |
7.93 g/cm3 |
1398-1454 ℃ |
500 J/(Kg·K) at 0-100℃ |
0.73 μΩ·m (20℃) |
17.2 (0-100℃) 17.8 (0-300℃ 18.4 (0-500℃) |
16.3 (100 ℃) |
18/8 stainless steel application
Food Industry: Commercial food processing equipment, brewery tanks, and dairy equipment.
Kitchenware: Sinks, holloware (pots/pans), cutlery, and flatware.
Architecture: Paneling, railings, and decorative trim.
Medical: Surgical instruments and medical implants.
Industrial: Heat exchangers, chemical containers, and fasteners.
18/8 vs. 18/10 vs. 18/0 Stainless Steels
| Grade | Equivalent Grade | Chromium | Nickel | Molybdenum | Magnetism | Typical Use |
|---|---|---|---|---|---|---|
| 18/0 | AISI 430 | 18% | 0% | No | Magnetic | Budget cookware |
| 18/8 | AISI 304 | 18% | 8% | No | Non-magnetic | Food equipment, kitchenware |
| 18/10 | AISI 304 / 304L | 18% | 10% | No | Non-magnetic | Premium cookware |
| 316 | 16–18% | 10–14% | 2–3% | Non-magnetic | Marine, chemical plants |
Is 18/8 stainless steel food safe?
Yes. Because it is equivalent to 304 stainless steel, 18/8 stainless steel is widely used in food processing equipment, cookware, beverage containers, and commercial kitchens.
Does 18/8 stainless steel rust?
Under normal conditions, it offers excellent resistance to rust. However, prolonged exposure to chlorides, seawater, or harsh chemical environments may eventually cause corrosion. For these applications, 316 stainless steel is recommended.
Is 18/8 stainless steel magnetic?
In the annealed condition, it is generally non-magnetic. After cold working or forming, slight magnetism may develop, which is normal and does not indicate inferior quality.
Is 18/8 better than 18/10?
18/10 offers marginally better surface luster and slightly higher corrosion resistance; for most applications, 18/8 provides the better cost-performance ratio.
How Can Buyers Verify Genuine 18/8 Stainless Steel?
Many importers have experienced quality issues caused by lower-grade materials being sold as "18/8." To reduce procurement risk, request the following documentation from your supplier:
EN 10204 3.1 Material Test Certificate (MTC)
Chemical composition report
Mechanical property report
PMI (Positive Material Identification) test report
Mill certificate
Surface finish inspection report
Dimensional inspection report
Third-party inspection (SGS, BV, TÜV) if required
Verifying these documents helps ensure the material matches the specified grade and meets project requirements.
Why Choose GNEE as Your 18/8 Stainless Steel Supplier?
With more than 18 years of export experience, GNEE supplies stainless steel products to customers in over 80 countries, serving industries including food processing, construction, petrochemical, marine engineering, and industrial manufacturing.
Our manufacturing capabilities include precision slitting, laser cutting, polishing, custom fabrication, and strict quality inspection. We provide products in accordance with international standards such as ASTM, ASME, EN, and JIS, with complete documentation including EN 10204 3.1 Material Test Certificates, chemical analysis reports, and third-party inspection support upon request.
Whether you require stainless steel sheets, coils, pipes, tubes, bars, or custom-fabricated components, our engineering team can recommend the most suitable grade, surface finish, and processing solution based on your application, helping reduce procurement risk and improve project efficiency.
