Understanding stainless steel fasteners isn’t just about knowing what “A2” or “A4” means; it’s about decoding a global language of material science, standardization, and mechanical performance.
In previous blogs, we explored the basic differences between A2 and A4 stainless steel. Now, in this expanded blog, we’re tackling how stainless fasteners are named, why different regions use different codes, and how to navigate the international stainless steel standardization alphabet soup.
In scientific terms, nomenclature is a system for naming things. In the world of fasteners, it’s how we classify stainless steel, whether you’re ordering in the U.S., Germany, or Japan. It’s also what helps you understand how 18-8 stainless steel, A2-70, or A4-80 all relate to each other (yes, they do!).
This system matters, especially when sourcing metric fasteners globally or comparing certifications across ASTM, ISO, DIN, ANSI, JIS, and other standards.
Let’s start with some metric fastener humor:
18-8 stainless steel walks into class. The teacher calls roll:
“18-8?”
It raises its hand: “It’s pronounced A2.”
18-8 is shorthand for 18% chromium and 8% nickel, a widely used austenitic stainless steel composition. But here’s where it gets tricky:
That’s where Eurolink’s expertise comes in, we help buyers, engineers, and sourcing teams translate this alphabet soup into the metric fasteners they actually need.
Let’s demystify what’s really in a stainless fastener name like A2-70.
Eurolink specializes in A-series fasteners, primarily A2 and A4, because of their superior corrosion resistance and compatibility with a wide range of industrial and outdoor applications.
The final number (e.g., -50, -70, -80) denotes tensile strength and yield strength.
|
Property Class |
Tensile Strength (MPa) |
Typical Use Case |
|
A2-50 |
500 MPa |
Light-duty, general use |
|
A2-70 |
700 MPa |
Most common for industrial use |
|
A4-80 |
800 MPa |
High-strength + high corrosion environments |
Did You Know? A4-80 stainless steel is one of Eurolink’s most in-demand fasteners for marine, food-grade, and chemical processing environments. We stock one of the largest inventories of A4-80 in North America.
If you’re sourcing from Germany or working with DIN specs, you may see terms like A2-12H or A2-25H.
These refer to specific property classes defined under DIN standards and are often used for special parts like set screws, dowels, or studs, not your everyday hex bolts.
Here’s how it works:
At Eurolink, we help you match the application with the correct grade and class, so you don’t have to memorize DIN specs or cross-reference ISO charts yourself.
Most fasteners labeled A2 or A4 fall under the austenitic stainless steel family.
This means they are:
Other types, like martensitic or ferritic steels, may have advantages in niche applications (e.g., high hardness or resistance to chloride), but they are magnetic and less commonly used for fasteners in global manufacturing.
A2 is general-purpose 18-8 stainless (comparable to 304). A4 contains molybdenum for extra corrosion resistance (comparable to 316) and is ideal for marine and chemical exposure.
Yes. A4-80 fasteners have a higher tensile strength and are better suited for high-load environments where corrosion resistance is also critical.
They’re often used interchangeably, but regional standards may vary slightly. Both describe an austenitic stainless with similar chemical makeup.
Yes. A4-70 has similar strength but better corrosion resistance. However, never downgrade strength classes without engineering approval.
Yes, we stock one of the largest selections of A4-80 stainless in North America, including bolts, screws, and specialty items.
Stainless steel fasteners are used in high-performance environments where strength and corrosion resistance are non-negotiable. But interpreting all the codes, names, and numbers can feel like learning a new language.
That’s where Eurolink Fastener Supply Service comes in.
We specialize in metric fasteners, including stainless grades like A2-70 and A4-80, hard-to-find DIN specs, and custom sourcing from trusted European manufacturers. Whether you're planning months ahead or facing a critical production delay, our FAST, FASTER, and FASTEST freight options give you flexible delivery solutions:
No matter your timeline, Eurolink helps you source metric fasteners with speed and confidence.