Choose 304 if your application is indoors, food-grade, or general industrial — it offers 90% of 316's performance at 55–65% of the cost.
Choose 316 if your project involves chlorides, saltwater, chemicals, or pharmaceuticals — the 2–3% molybdenum content provides critical corrosion resistance that 304 cannot match.
Cost gap: 316 typically costs $800–1,500/ton more than equivalent 304 products. For a 10-ton order, that's a $8,000–15,000 difference.
The fundamental difference between 304 and 316 stainless steel is molybdenum. 316 contains 2–3% molybdenum, which 304 lacks entirely. This single element transforms the material's resistance to chlorides and acids.
| Element | 304 (UNS S30400) | 316 (UNS S31600) | What It Affects |
|---|---|---|---|
| Carbon (C) | ≤ 0.08% | ≤ 0.08% | Weldability, sensitization risk |
| Chromium (Cr) | 18.0–20.0% | 16.0–18.0% | General corrosion resistance |
| Nickel (Ni) | 8.0–10.5% | 10.0–14.0% | Ductility, formability, acid resistance |
| Molybdenum (Mo) | — | 2.0–3.0% | Pitting & chloride resistance ← KEY DIFFERENCE |
| Manganese (Mn) | ≤ 2.0% | ≤ 2.0% | Strength, deoxidation |
| Silicon (Si) | ≤ 0.75% | ≤ 0.75% | Oxidation resistance |
| Phosphorus (P) | ≤ 0.045% | ≤ 0.045% | Brittleness control |
| Sulfur (S) | ≤ 0.030% | ≤ 0.030% | Machinability |
| Iron (Fe) | Balance | Balance | Base metal |
Low-carbon variants: 304L (≤0.03% C) and 316L (≤0.03% C) eliminate sensitization during welding — always specify L-grade for welded assemblies over 5mm thickness.
Key insight: Molybdenum in 316 costs roughly $8–12 per kilogram at LME prices (2026). For a standard 2mm sheet, this adds ~$160–240/ton in raw material cost before processing.
304 and 316 have very similar mechanical properties. The difference is small enough that design calculations rarely change when substituting one for the other.
| Property | 304 | 316 | Winner |
|---|---|---|---|
| Tensile Strength (MPa) | 515–620 | 515–620 | ≈ Tie |
| Yield Strength 0.2% (MPa) | 205–310 | 205–310 | ≈ Tie |
| Elongation (%) | 40–60 | 40–60 | ≈ Tie |
| Hardness (Rockwell B) | 70–90 | 70–90 | ≈ Tie |
| Modulus of Elasticity (GPa) | 193–200 | 193–200 | ≈ Tie |
| Density (g/cm³) | 7.93 | 7.98 | ≈ Tie |
| Thermal Conductivity (W/m·K) | 16.2 | 16.3 | ≈ Tie |
| Electrical Resistivity (μΩ·cm) | 72 | 74 | ≈ Tie |
| Max Service Temperature (°C) | 870 | 870 | ≈ Tie |
Conclusion on mechanics: The two grades are effectively interchangeable. Your decision will not be driven by strength, hardness, or temperature tolerance — it comes down to corrosion environment and budget.
This is where 304 and 316 diverge. The molybdenum in 316 provides dramatically better resistance in chloride-containing environments.
| Environment | 304 Performance | 316 Performance |
|---|---|---|
| Fresh water | ✅ Excellent | ✅ Excellent |
| Atmospheric (rural/urban) | ✅ Excellent | ✅ Excellent |
| Food processing (acids) | ✅ Good | ✅ Excellent |
| Dairy & brewing | ✅ Good | ✅ Excellent |
| Seawater / Salt spray | ⚠️ Limited (pitting after 6-12 mo) | ✅ Good (pitting after 3-5 yr) |
| Chlorides (>200 ppm) | ⚠️ Pitting risk | ✅ Resistant up to 1000 ppm |
| Chemical / Acidic (H₂SO₄, HCl diluted) | ⚠️ Limited | ✅ Good |
| Pharmaceutical / Clean rooms | ⚠️ Acceptable | ✅ Required by standards |
| Coastal architecture | ⚠️ Surface staining (1-3 yr) | ✅ Maintains appearance (5-10 yr) |
| Deicing salt (roads/structures) | ❌ Not recommended | ⚠️ Use 316L |
PREN = %Cr + 3.3 × %Mo + 16 × %N. This is the industry-standard formula for comparing pitting corrosion resistance:
A PREN above 24 is generally recommended for marine environments. 316 clears this threshold; 304 does not.
This is the most practical section for buyers. Below are real-market prices for FOB China stainless steel products (Q2 2026).
| Product Form | 304 (2B) | 316L (2B) | Price Gap | 316 Premium |
|---|---|---|---|---|
| 0.5mm sheet | $2,900–3,200 | $4,300–4,800 | $1,100–1,600 | +38–50% |
| 1.0mm sheet | $2,700–3,000 | $4,000–4,500 | $1,000–1,500 | +37–50% |
| 2.0mm sheet | $2,500–2,800 | $3,700–4,200 | $900–1,400 | +36–50% |
| 3.0mm plate | $2,400–2,700 | $3,500–4,000 | $800–1,300 | +33–48% |
| 6.0mm plate | $2,300–2,600 | $3,300–3,800 | $700–1,200 | +30–46% |
| 10mm plate (HR) | $2,200–2,500 | $3,100–3,500 | $600–1,000 | +27–40% |
| Product Form | 304 | 316L | 316 Premium |
|---|---|---|---|
| Welded pipe SCH 10S | $3,200–3,800 | $5,000–5,800 | +45–53% |
| Welded pipe SCH 40S | $3,500–4,200 | $5,400–6,300 | +44–54% |
| Seamless pipe SCH 40S | $4,200–5,000 | $6,500–7,500 | +45–55% |
| Square tube 40×40×2mm | $3,000–3,500 | $4,600–5,200 | +43–53% |
| Sanitary tube BA | $3,800–4,500 | $5,600–6,500 | +40–47% |
Scenario: 2.0mm 304 2B sheet vs 316L 2B sheet, 10 metric tons
| 304 cost | $26,500 | (at $2,650/ton average) |
| 316L cost | $39,500 | (at $3,950/ton average) |
| Difference | $13,000 | +49% more for 316L |
Over a 20-ton project (common for a mid-size building facade or food processing plant), the gap widens to $26,000 — a meaningful budget decision.
| Cost Component | 304 | 316 | Reason |
|---|---|---|---|
| Raw material (Ni + Mo) | $800–1,000/t | $1,600–2,200/t | 2× more Ni + Mo addition |
| Melting & casting | $200–300/t | $250–350/t | 316 needs tighter composition control |
| Hot rolling | $150–250/t | $150–250/t | Similar process |
| Cold rolling + annealing | $200–400/t | $250–450/t | 316 needs slower annealing (more passes) |
| Surface finishing | $100–200/t | $100–200/t | Similar cost |
| Total manufacturing | $1,450–2,150/t | $2,350–3,450/t | +55–65% higher |
Key insight: Roughly 70% of the price premium comes from raw materials (more nickel + molybdenum). Only 30% comes from additional processing. The LME nickel price directly impacts the gap — when nickel is high ($20,000+/t), the 304/316 spread widens.
304 is the world's most popular stainless steel grade for good reason. In approximately 75–80% of stainless steel applications, 304 is the correct choice.
316 is the specialist. Use it when the environment contains chlorides, strong acids, or requires regulatory compliance.
| Environment | 304 Lifespan | 316 Lifespan | Upfront Premium | 20-Year Cost (304) | 20-Year Cost (316) | Savings with 316 |
|---|---|---|---|---|---|---|
| Coastal building facade | 8–12 yr (replace x1) | 20+ yr (no replace) | +40% | $53,000 | $39,500 | $13,500 saved |
| Seafood processing plant | 3–5 yr (replace x3) | 12–15 yr (replace x0.5) | +45% | $79,500 | $47,400 | $32,100 saved |
| Chemical storage tank | 2–4 yr (fail) | 10–15 yr | +50% | $79,500 | $39,750 | $39,750 saved |
| Indoor kitchen (dry) | 15–20 yr | 20+ yr | +40% | $26,500 | $39,500 | $13,000 extra ← overpay |
Bottom line: In aggressive environments, 316's longer lifespan more than compensates for its higher upfront cost. In benign environments, 304 is more economical by a wide margin.
False. As shown in the mechanical properties table, tensile and yield strengths are nearly identical. 316's advantage is corrosion resistance, not strength.
No stainless steel is rust-proof. 316 resists corrosion much longer than 304 in chlorides, but it can still pit in extreme conditions (high temperature, high chloride, stagnant seawater). For true immunity, use super duplex (2507) or titanium.
Incorrect. 304 (18/8) is the standard food-grade stainless steel worldwide. It meets FDA, NSF, and EU food contact regulations. 316 is only required when the food involves salt, acid, or high-temperature cleaning.
Not if you're cost-sensitive. Specifying 316 for an indoor handrail or kitchen backsplash adds 40–50% cost with zero benefit. Engineers call this "gold-plating" — avoid it.
Both are austenitic and normally non-magnetic. But cold working (bending, stamping) can make either grade slightly magnetic. The magnet test is unreliable for distinguishing them.
It depends on location. For inland areas (more than 10 km from coast), 304 performs well for 15+ years. For coastal areas, 316 is strongly recommended — expect 304 to show surface pitting within 1–3 years in salt spray.
Not recommended. 304 will pit in seawater within 6–12 months. 316 performs better (3–5 years before visible pitting) but for permanent seawater immersion, consider 2205 duplex or 2507 super duplex.
As of mid-2026, 316 costs approximately 35–55% more than 304 depending on product form. Sheet/plate premium is 30–50%, pipe/tube premium is 40–55%. The gap fluctuates with LME nickel and molybdenum prices.
Request a PMI (Positive Material Identification) test using XRF spectrometer — it detects molybdenum instantly. Reputable Chinese mills provide Mill Test Certificates (MTC) per EN 10204 3.1. Third-party inspection (SGS, BV, Intertek) is recommended for large orders.
L-grade (low carbon) is preferred for laser cutting thicker plates (≥5mm) to avoid carbide precipitation at the heat-affected zone. For thin sheet (<3mm) laser cutting, standard 304 or 316 is fine.
316 is required for applications involving brine, salt solutions, or chlorinated cleaning agents. For dry food or fresh-water processing only, 304 is sufficient and more cost-effective.
Still unsure? FANY LASER's technical team can help you evaluate your specific environment. We supply both 304 and 316 in all forms — sheet, plate, pipe, tube, and custom fabricated parts — with full MTC and third-party inspection support.
Not sure which grade fits your project? Send us your application details and we'll recommend the optimal material — with cost comparison.
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