When sourcing divided plates for commercial food service, school cafeterias, or retail distribution, the single most important decision is the steel grade. The wrong material can leach heavy metals, corrode within months, or fail food-safety audits.
This guide covers why 304 stainless steel is the industry benchmark for food-contact divided plates, how it compares to cheaper alternatives, and how to verify the grade before placing a bulk order.
1. Why 304 Is the Gold Standard
304 stainless steel (SUS304 / 18-8) contains approximately 18% chromium and 8% nickel, creating a stable, self-healing chromium-oxide layer on the surface.
Corrosion Resistance — Withstands acidic foods (tomato sauce, citrus, vinegar) without pitting.
Zero Metal Leaching — Meets FDA 21 CFR, EU 1935/2004, and LFGB migration standards.
Dishwasher Durability — Handles commercial cycles (up to 82 °C rinse) without surface damage.
Structural Longevity — 10+ years of daily institutional use. Superior ductility handles deep-draw forming without micro-cracking at compartment walls.
Divided plates have stamped compartment walls that create stress points during forming. Lower-grade steels are prone to micro-cracking at these points, which traps bacteria and accelerates corrosion. 304's ductility eliminates this risk.
2. 304 vs 201 vs 430 Composition
The three grades most commonly found in divided plate manufacturing:
| Property | SUS304 (18/8) | SUS201 (17/4.5) | SUS430 (17/0) |
|---|
| Chromium | 18 – 20% | 16 – 18% | 16 – 18% |
| Nickel | 8 – 10.5% | 3.5 – 5.5% | ≤ 0.75% |
| Manganese | ≤ 2% | 5.5 – 7.5% | ≤ 1% |
| Carbon | ≤ 0.08% | ≤ 0.15% | ≤ 0.12% |
| Structure | Austenitic | Austenitic | Ferritic |
| Magnetic | No (slight after cold work) | Slightly | Yes |
| Corrosion | Excellent | Moderate | Moderate |
| Food-Safety | FDA / LFGB / DGCCRF | Limited — often fails EU tests | FDA only (not for acidic food) |
| Typical Use | Schools, hospitals, airlines | Low-cost domestic | Non-food industrial |
| Relative Cost | 1.0x | ~0.7x | ~0.75x |
Key Takeaways
Nickel is the differentiator. 304's 8–10.5% nickel stabilizes the austenitic structure for superior corrosion resistance. 201 substitutes manganese for nickel — lower cost, lower protection.
201 fails export compliance. Frequently fails EU heavy-metal migration testing for nickel and manganese release. Not recommended for Europe, North America, or Japan markets.
430 is ferritic and magnetic. Suitable for dry industrial trays. Not recommended for prolonged food contact with acidic or salty foods.
3. How to Verify the Grade
Three methods, from quickest field check to definitive lab result:
Magnet Test
Quick Field Check
Hold a neodymium magnet against the plate. 304 is non-magnetic on flat surfaces. 201 clings firmly. 430 is strongly magnetic.
Limitation: Screening only. Cold-worked 304 may show slight attraction.
Spark Test
Workshop Method
Touch sample edge to a bench grinder. 304 produces short, orange sparks with few forks. 201 produces longer, brighter, more branched sparks.
Limitation: Requires experience. Only for raw material or cut samples.
Material Certificate & XRF Analysis
Definitive Verification
Mill Test Certificate (MTC): Steel mill's certificate listing exact composition (Cr, Ni, Mn, C, Si, S, P) and heat number. Cross-reference against ASTM A240 or JIS G4305.
XRF Handheld Analyzer: Alloy composition readout in under 30 seconds on finished products. Non-destructive.
Buyer Tip
When evaluating a new supplier, request three documents: (1) MTC for the specific coil lot, (2) third-party FDA or LFGB food-contact test report, (3) a sample for your own XRF spot-check. This three-layer verification eliminates grade substitution risk.
4. Use Cases by Sector
The same 304 grade is configured differently for each end-use environment:
| Sector | Configuration | Surface Finish | Why 304 |
|---|
| School Cafeteria | 4–6 compartments, 26–28 cm, stackable, rounded edges | Mirror polish / matte satin | FDA, GB 9684, LFGB compliant without coatings |
| Hospital | 3–5 compartments, deeper wells, fitted lid | Mirror polish | Autoclavable at 121 °C; MTC traceability required |
| Restaurant / Thali | 5–7 compartments, 30–40 cm, round or rectangular | PVD coating (gold, rose gold, black) | Stable oxide layer bonds cleanly with PVD titanium nitride |
| Airline Catering | Custom layout for ATLAS/KSSU carts, 0.5–0.7 mm gauge | Standard polish / matte | Thinner gauge than 201 with same strength; weight savings |
Frequently Asked Questions
What is the chemical composition of 304 stainless steel?
18–20% chromium, 8–10.5% nickel, ≤2% manganese, ≤0.08% carbon. This 18/8 composition creates a stable austenitic crystal structure with superior corrosion resistance.
How to check the grade — 304 or 202?
Three methods: (1) Magnet test — 304 is non-magnetic, 201/202 clings to magnets. (2) Spark test — 304 produces short orange sparks. (3) XRF analysis or Mill Test Certificate — definitive alloy composition.
Is 201 stainless steel safe for food?
201 meets basic standards in some domestic markets but frequently fails EU migration testing due to higher manganese and lower nickel. For export (EU, US, Japan), 304 is the safe choice.
Why are 304 divided plates more expensive than 201?
Approximately 30% higher cost driven by nickel content. Offset by longer lifespan, lower replacement rate, and zero compliance risk.
Najor 304 Divided Plate Product Line
At Najor Cookware, SUS304 is the default material — not an upgrade. Every divided plate starts with verified SUS304 coils backed by mill test certificates.
Material SUS304 (18/8) — coil-level MTC verification
Established Since 1992 — 30+ years manufacturing
Capacity 400,000+ pieces/month
QC 7-point inspection system
Certifications FDA, LFGB, DGCCRF, CE
Customization Layout, diameter (18–40 cm), finish, logo, packaging
MOQ 100 pcs (stock) / 5,000 pcs (OEM)
Lead Time Sample 7D / Production 25–30D
Contact: sales@najorcookware.com | www.najorcookware.com