Why Chinese 201 J1 J3 J4 Stainless Steel Is Not the Same as UNS S20100
When international buyers search for 201 stainless steel, many expect a global standard — like UNS S20100, listed under ASTM specifications. However, the 201 stainless steel widely used in China is not the same, and that causes confusion in global sourcing, quality control, and certification.
So, what exactly is “201 stainless steel” in China, and why is it different from the international version?
✅ 1. 201 Was Never a Fully Unified Standard
Unlike 304 or 316, which are clearly defined by ASTM and EN standards, 201 stainless steel originated as a low-nickel alternative, first developed in India. It uses higher manganese and nitrogen to replace expensive nickel.
China adopted the idea, but developed its own commercial variants to suit different application needs and price ranges.
✅ 2. China’s 201 Stainless Has Evolved Into “J-Series Grades”
In the Chinese market, 201 has been split into subgrades — commonly known as J1, J3, J4, J2, J5. These are not part of any international standard like ASTM A240 or UNS S20100.
Here’s a simplified comparison:
| Grade | Cu (%) | C (%) | Notes |
|---|---|---|---|
| 201 J4 | 1.4–1.5 | ≤ 0.10 | Best ductility, good polishability |
| 201 J1 | 0.7–0.8 | ≤ 0.10 | Balanced cost and performance |
| 201 J3 | 0.45–0.55 | ≤ 0.14 | Economical, less ductile |
| 201 J2 | 0.25–0.35 | ≤ 0.16 | Lower Cu, lower corrosion resistance |
| 201 J5 | < 0.25 | ≤ 0.18 | Budget grade, basic performance |
🔍 Main differences come from copper (Cu) and carbon (C). These affect corrosion resistance, surface finish quality, and mechanical strength. Other elements like Cr, Ni, Mn remain roughly in standard 201 ranges.
✅ 3. Not Recognized Under ASTM A240 or UNS S20100
While your technical datasheet might refer to UNS S20100 / ASTM A240 / ASTM A666, it’s important to know:
Chinese 201 (J1–J5) is not produced or certified under these standards.
So unless the mill specifically confirms strict compliance (which is rare), Chinese 201 cannot be considered fully ASTM-compliant — especially for regulated or structural applications.
✅ 4. What Certificates Are Available?
Though not ASTM-certified, most Chinese suppliers (including us) can provide:
- ✅ EN 10204 – 3.1 Mill Test Certificate (MTC)
- ✅ Full chemical composition and mechanical properties
- ✅ Heat / coil number traceability
This allows for internal QC and verification, and is acceptable for most commercial, decorative, and light industrial uses.
✅ 5. What Should You Do as a Buyer?
- Ask clearly whether the 201 offered is J1, J3, J4 or other grade
- Don’t assume compliance with UNS S20100 / ASTM A240 unless confirmed
- Request MTCs to verify composition and traceability
- Match the grade to your application (e.g. welding, bending, polishing, corrosion resistance)
📌 Final Thoughts
Chinese 201 stainless steel is not “fake”, but it is fundamentally different from international standards. Understanding this difference helps you make smarter sourcing decisions — and avoid costly misunderstandings.
If you’re unsure which grade fits your needs, we’re always happy to offer technical support and sample data.
Here are some sample MTC from Lisco (201 LH) and Baosteel (201 J1) :
- LISCO’s spec says >50% elongation, but in reality their 201 LH is usually just over 40%.
