This is a very specific and important issue. It needs to be clearly stated that **for SUS430 stainless steel, the global standard requirement for nickel content is "≤0.60%", and it is generally required that "it must not be intentionally added".** It is a typical **nickel-free or low-nickel ferritic stainless steel**.

The following are the detailed provisions of the global standards, which are highly consistent on this issue:

 1. **Japanese Standard JIS G 4303/4305 (SUS430)**

- **Ni (Nickel): ≤ 0.60%**

- **Key Point**: The standard explicitly states that "it can contain no more than 0.60% nickel," but this portion of nickel **is not intentionally added to adjust the microstructure and properties**, but exists as a residual element, mainly from the scrap steel raw materials used in smelting.

 2. **Chinese Standard GB/T 3280 (06Cr17 or old grade 0Cr17)**

- **Ni (Nickel):** ≤ 0.60%

- Substantially equivalent to JIS standard, also specifying an upper limit for residual elements.

 3. **American Standard ASTM A240 (Type 430)**

- **Ni (Nickel):** ≤ 0.50%** (May be ≤ 0.60% in some versions or under certain conditions)

- Also emphasizes "not actively added," controlled as a residual element.

 4. **European Standard EN 10088-2 (1.4016)**

- **Ni (Nickel):** Not specified (or according to agreement), but in actual production and commercial contracts, it is usually still controlled with reference to the upper limit of ≤ 0.60% to ensure its "nickel-free" ferritic properties.

 **Core Summary and Explanation:**

1. **"≤0.60%" is a universal requirement:** Although different standards may have slight differences in wording and precise values ​​(e.g., 0.50% or 0.60%), in global trade and actual production, **controlling the nickel content below 0.60%** is a recognized and universally accepted technical requirement and acceptance benchmark.

2. **"No intentional addition" is essential:** The core design principle of SUS430's chemical composition is **high chromium (approximately 16-18%), low carbon, and nickel-free**. Its corrosion resistance mainly relies on the oxide film formed by chromium. Intentionally adding nickel would alter its metallographic structure (becoming austenitic or duplex steel), thus losing its characteristics as an inexpensive, low-thermal-expansion, magnetic ferritic steel.

3. **Why is ≤0.60% nickel allowed?**

- **Technical reasons:** When using scrap steel for electric arc furnace smelting, the scrap steel inevitably contains nickel-containing steel (such as 304 stainless steel). Completely separating these nickel particles is extremely costly industrially.

- **Performance Reasons:** As long as the nickel content is below this threshold, it dissolves in the matrix as a residual element, **not significantly altering the ferritic single-phase structure of SUS430**, and has no major impact on its basic properties.

- **Economic Reasons:** Allowing a certain residual content can significantly reduce production costs, allowing SUS430 to maintain its economic advantage.

4. **Comparison with Nickel-Containing Stainless Steel:**

- **SUS304 (Austenitic Stainless Steel):** Nickel content requirement is **8.0-11.0%**, a key alloying element that must be actively added.

- **SUS430:** Nickel content requirement is **≤0.60%**, a residual element that must be strictly controlled.

**Conclusion:** When sourcing or accepting SUS430 stainless steel globally, you can explicitly require that its **nickel (Ni) content not exceed 0.60% (usually controlled at the 0.60% upper limit)**, and that it be a residual element, not actively added. This is a key indicator to ensure that materials meet standards, have the correct performance, and are cost-effective.