Contents
A2 Stainless Steel: Properties, Characteristics And Comparison
- John
A2 stainless steel is highly regarded for its exceptional corrosion resistance and durability. It has become a popular choice for tools and fasteners designed to endure tough and demanding conditions.
This article provides a comprehensive overview of A2 stainless steel, covering its composition, properties, and applications. It also explores the different subgrades—A2-50, A2-70, and A2-80—and offers a comparison between A2 stainless steel and other stainless steel grades such as 304, A4, and A8.
What Is A2 Stainless Steel?
A2 stainless steel is an austenitic stainless steel. It contains about 65-70% iron (Fe) content, 18-20% chromium (Cr) content, and 8-10.5% nickel (Ni) content, with small amounts of carbon, manganese, and silicon. It has a silvery, slightly reflective surface. Its corrosion resistance is great. And it has a balance of durability and workability. Its common uses include kitchen equipment, architectural elements, automotive components, and chemical containers.
- Is A2 Stainless Steel the Same as 304?
Not the same but they are closely related. 304 is an international alloy classification. A2 is a European designation commonly used for stainless steel fasteners and typically refers to 304 stainless steel.
Equivalents of A2 Stainless Steel
| Country/Region | Standard/Specification | Equivalent Grade |
| China | GB/T 1220, GB/T 20878 | 06Cr19Ni10 (or 304) |
| USA | ASTM A276, ASTM A240 | 304 |
| EU | EN 10088-2 | X5CrNi18-10 (1.4301) |
| Germany | DIN EN 10088-2 | X5CrNi18-10 |
| Japan | JIS G4303 | SUS304 |
| England | BS EN 10088-2 | 304S15 |
Subgroups of A2 Stainless Steel
A2 stainless steel, widely recognized for its excellent corrosion resistance in non-marine environments, is categorized into three subgrades: A2-50, A2-70, and A2-80. These classifications are based on their tensile strength and mechanical properties, making them suitable for a variety of applications:
- A2-50: Ideal for low-stress, flexible applications and is the most cost-effective option.
- A2-70: The most commonly used grade, popular in fasteners like bolts and nuts due to its balance of strength and affordability.
- A2-80: Offers the highest strength with reduced ductility, making it extremely durable but also the most expensive choice.
Here’s a table comparing A2-50, A2-70, and A2-80 stainless steel materials for tensile strength, cost, and other key properties:
| Properties | A2-50 | A2-70 | A2-80 |
| Tensile Strength | ≥500 N/mm² | ≥700 N/mm² | ≥800 N/mm² |
| 0.2% Yield Strength | ≥210 N/mm² | ≥450 N/mm² | ≥600 N/mm² |
| Elongation | ≥0.6d | ≥0.4d | ≥0.3d |
| Applications | Light-duty like low-stress components) | General-purpose like fasteners | Heavy-duty like automotive parts |
| Cost | Low | Moderate | High |
Composition of A2 Stainless Steel
| Element | Cr | Ni | C | Mn | P | S | Si | N |
| wt% | 18.0 – 20.0 | 8.0 – 10.5 | ≤ 0.08 | ≤ 2.0 | ≤ 0.045 | ≤ 0.03 | ≤ 1.0 | ≤ 0.10 |
Mechanical Properties of A2 Stainless Steel
| Property | Value |
| Tensile Strength | 515 – 740 MPa |
| Yield Strength | 205 MPa (min) |
| Brinell Hardness (HB) | 123 – 201 HB |
| Rockwell Hardness (HRC) | 70 – 88 HRC |
| Vickers Hardness (HV) | 129 – 200 HV |
| Elongation | 40% (in 50mm) |
| Elastic Modulus | 193 GPa |
Physical Properties of A2 Stainless Steel
| Property | Typical Value (Metric) | Typical Value (Imperial) |
| Density | 7.75 g/cm³ | 0.280 lb/in³ |
| Melting Point | 1,480°C | 2,696°F |
| Thermal Conductivity | 24.9 W/m·K | 173 BTU·in/hr·ft²·°F |
| Thermal Expansion | 10.2 µm/m·°C | 5.7 µin/in·°F |
| Electrical Conductivity | 1.25 x 10⁶ S/m | 2.15% IACS |
- Is A2 Stainless Steel Magnetic?
In its annealed state, A2 stainless steel is not magnetic. But it can be slightly magnetic when cold-worked or welded. This is important in applications where magnetic properties are a factor.
Performance of A2 Stainless Steel
Excellent Corrosion Resistance
A2 stainless steel contains high chromium content. So its corrosion resistance is excellent. This makes it suitable for environments where the material is exposed to acids, moisture, and alkalis. It is suitable for applications like kitchen equipment, chemical containers, and architectural elements.
Limitation
It is not suitable for marine environments or chloride-rich applications due to susceptibility to pitting and stress corrosion cracking. For these environments, higher-grade stainless steels like A4 (316) are recommended.
Moderate Heat Resistance
A2 stainless steel can withstand continuous operating temperatures up to 870°C and short-term exposure up to 925°C. Its performance makes it suitable for applications involving moderate heat exposure, such as industrial piping, cookware, and heat exchangers.
Limitation
A2 stainless steel experiences carbide precipitation between 425°C and 870°C, reducing corrosion resistance in welded areas. Its strength also decreases above 500°C, limiting use in high-stress, high-temperature applications.
Moderate Strength
A2 stainless steel offers moderate strength, with a tensile range of 500–750 N/mm², suitable for structural and industrial use. It balances durability and ductility.
Limitation
It is not ideal for high-strength or heat-intensive applications due to its alloy composition and performance limitations at elevated temperatures.
Ease of Forming
A2 stainless steel is highly workable, allowing it to be easily shaped and formed. This is ideal for manufacturing processes that require bending, stamping, or shaping the material into complex forms.
Cold Resistance
A2 stainless steel retains its strength at very low temperatures, withstanding conditions down to -196°C (-321°F). It is useful for cryogenic applications and other environments that require high toughness.
Excellent Weldability
A2 stainless steel is highly weldable due to its austenitic microstructure. It is suitable for most common welding techniques, including TIG, MIG, and resistance welding without requiring post-weld heat treatment in most cases.
However, precautions are needed to avoid carbide precipitation in the heat-affected zone (HAZ) at temperatures between 425°C and 870°C.
Aesthetic Versatility
A2 stainless steel can be polished to a smooth, reflective finish, making it an attractive option for visible or decorative applications.
- Is A2 Easy to Sharpen?
Yes, A2 stainless steel is relatively easy to sharpen because its hardness is balanced with a fine grain structure, which helps achieve a sharp edge without excessive difficulty. A2 can be a good knife.
What Is the A2 Stainless Steel Used for?
A2 stainless steel is most widely used in the production of fasteners. Here’s a look at the main fields of applications of A2 stainless steel.
| Application | Uses | Properties |
| Food & Beverage | Kitchen equipment, storage tanks | Corrosion-resistant, hygienic |
| Construction & Architecture | Building facades, railings | Durable, aesthetic |
| Automotive | Exhaust systems, trim | Heat, corrosion resistant |
| Medical Equipment | Surgical tools, devices | Non-reactive, sterilizable |
| Chemical Processing | Tanks, pipes | Acid, alkali resistant |
Common Product Forms of A2 Stainless Steel
Sheets and Plates
A2 stainless steel is commonly rolled into thin sheets or thick plates, available in various dimensions. Its smooth surface is easy to clean and maintain, making it ideal for food-grade and hygienic applications.
- Fabrication of kitchen equipment, countertops, and sinks.
- Used in industrial machinery for enclosures and structural panels.
Bars and Rods
A2 stainless steel is produced in round, square, or flat bar forms for manufacturing precision components. It offers a good combination of machinability and corrosion resistance, making it reliable for precision work.
- Machined into shafts, pins, and gears in mechanical engineering.
- Used in decorative elements such as railings and handles.
Tubes and Pipes
Tubular forms of A2 stainless steel, including seamless and welded pipes, are widely available. Its non-magnetic and anti-corrosive properties are suitable for non-critical piping applications.
- Plumbing systems in residential and commercial buildings.
- Automotive exhaust systems require moderate corrosion resistance.
Wires
A2 stainless steel wires are manufactured in various diameters and forms, such as coils or straight lengths. Its high strength, resistance to wear, and excellent flexibility make it ideal for dynamic or high-precision uses.
- Formed into wire mesh for filtration, fencing, or reinforcement.
- Used for springs in mechanical systems or precision equipment.
Differences Between A2, A4 And, A8 Stainless Steel
Under the ISO 3506 standard, austenitic stainless steels are classified as A1, A2, A3, A4, A5, and A8. Among these, A2, A4, and A8 are widely used, with A2 stainless steel being the most common due to its excellent versatility and corrosion resistance.
A4 vs A2 or 316 vs 304
A2 stainless steel provides good corrosion resistance in everyday environments but is less effective in high-chloride areas. A4 stainless steel resists chlorides and acids better. It is more expensive than A2.
A2 is used in general applications like kitchen equipment and indoor structures. A4 is preferred for harsher environments such as marine settings and chemical plants.
A8 vs A2
A8 stainless steel offers excellent wear resistance but lower corrosion resistance compared to A2.
A8 is extremely durable but harder to work with and less ductile. A2 stainless steel is easier to form and weld.
A2 is used in kitchenware, fasteners, and indoor structures. A8 is used in wear-intensive applications like cutting tools and industrial machinery.
A2 Stainless Steel vs 18-8
A2 stainless steel and 18-8 stainless steel are essentially the same in terms of composition. “18-8” is a general description for this type of stainless steel, while “A2” is a specific European designation, commonly used in fasteners.
High-quality A2 Stainless Steel Products
If you’re searching for high-quality, specification-compliant products with consistent performance for your fastener production or other products, SteelPro Group offers uniform and superior A2 stainless steel wire, bars, and more, along with a variety of surface treatments and customization options.
Our goal is to help your project succeed at every step with our high-quality products. Trust SteelPro Group to provide the excellence you need for reliable and efficient manufacturing.
