Stainless Steel Coils Supplier | Manufacturer
Thickness: 0.03 mm to 45 mm, or as customers’ demands.
Sizes: 1000/1219/1500/1800/2000, etc. Or as your requirement.
Finish: No.1, 2B, No.4, BA, Embossed, Etch, etc.
Manufacturers: TISCO, BAOSTEEL, JISCO, etc.
Types: stainless steel hot rolled coils and cold rolled stainless steel coils, color coated ss coil, etc.
Standard: AISI 304/304L, ASTM A240, ASTM A480, GB／T3280-2007, JIS G4304-2005, etc.
304L Stainless Steel of Specification and Size
304L stainless steel coil, also known as 18-8 stainless steel, is the most widely used austenitic stainless steel in the world. It is renowned for its excellent corrosion resistance, heat resistance, and formability. This alloy has become a staple in various industries due to its versatile properties and cost-effectiveness. Whether it’s for kitchen appliances, medical instruments, or architectural components, 304 stainless steel sheet offers a reliable and durable solution.
Alloy Specification
304 and 304L stainless steel coils are austenitic chromium-nickel alloys (18% Cr, 8% Ni) renowned for their corrosion resistance, formability, and versatility.
- 304L is a low-carbon variant (≤0.03% C) of 304 (≤0.08% C), designed to enhance weldability and intergranular corrosion resistance in harsh environments.
- Both grades comply with ASTM A240/A240M, UNS S30400 (304), and UNS S30403 (304L).
Chemical Composition of 304L Stainless Steel Coil
| Element | 304 (%) | 304L (%) | Effect on Performance |
|---|---|---|---|
| Chromium (Cr) | 18.0-20.0 | 18.0-20.0 | Corrosion resistance |
| Nickel (Ni) | 8.0-10.5 | 8.0-12.0 | Austenite stability |
| Carbon (C) | ≤0.08 | ≤0.03 | Reduces weld decay |
| Manganese (Mn) | ≤2.0 | ≤2.0 | Strengthening |
| Silicon (Si) | ≤0.75 | ≤0.75 | Deoxidation |
| Phosphorus (P) | ≤0.045 | ≤0.045 | Improves machinability |
| Sulfur (S) | ≤0.03 | ≤0.03 | Affects hot workability |
Physical Properties of Stainless Steel
| Property | 304 | 304L | Comparison vs. 316 |
|---|---|---|---|
| Density (g/cm³) | 8.0 | 8.0 | Same |
| Melting Range (°C) | 1400-1450 | 1400-1450 | Similar |
| Thermal Conductivity (W/m·K) | 16.2 | 16.2 | Lower than carbon steel |
| Electrical Resistivity (μΩ·m) | 0.72 | 0.72 | Higher than copper |
| CTE (μm/m·°C, 20-100°C) | 17.2 | 17.2 | Higher than ferritic SS |
Mechanical Properties of Stainless Steel
| Property | 304 | 304L | 316 (Reference) |
|---|---|---|---|
| Tensile Strength (MPa) | 515 | 485 | 515 |
| Yield Strength (MPa) | 205 | 170 | 205 |
| Elongation (%) | 40 | 40 | 40 |
| Hardness (Rockwell B) | 70-90 | 70-90 | 80-95 |
| Fatigue Strength (MPa, 10⁷ cycles) | 240 | 240 | 260 |
Benefits of Using 304L Stainless Steel Coil
✔ Superior Corrosion Resistance
Resists freshwater, acids, and oxidizing environments
Performs better than 316 in nitric acid but worse in chlorides
✔ Excellent Formability
Deep drawing, spinning, and bending compatible
Lower work hardening rate vs. 301/302
✔ Weldability
304L preferred for welding (no carbide precipitation)
No preheat/post-weld heat treatment required
✔ Cost-Effective
30% cheaper than 316 while offering similar strength
✔ Hygienic & Aesthetic
Easy to clean, ideal for food processing & architecture
Tips for Procurement and Cost-Effectiveness
- Supplier Selection: Choose reputable suppliers with a track record of quality control and timely delivery. Look for suppliers that offer certifications such as ISO 9001 and ASTM compliance.
- Material Grade: Ensure the material grade matches the required specifications (e.g., AISI 304, ASTM A240).
- Surface Finish: Select the appropriate surface finish based on the application (e.g., 2B, #4, #8 mirror).
- Quantity and Size: Consider the required quantity and sheet size to optimize material usage and reduce waste.
A. Production Process
Hot rolling → Cold rolling → Annealing & Pickling
Surface finishes: 2B (smooth), BA (bright annealed), No.4 (brushed)
B. Cost Comparison (Per kg, 2023 Market Data)
| Material | Price (USD/kg) | Key Cost Factor |
|---|---|---|
| 304 Coil | 3.50−4.50 | Nickel market volatility |
| 304L Coil | 3.70−4.80 | Lower carbon = higher refining cost |
| 316 Coil | 6.00−8.00 | Molybdenum content |
| Carbon Steel Coil | 0.80−1.20 | No alloying elements |
C. Machining & Fabrication
Machinability: 45% (vs. 100% for free-cutting brass)
Cutting speed: 30-50 m/min (carbide tools recommended)
Welding methods: TIG, MIG, SAW (ER308L filler for 304L)
Applications of 304L Stainless Steel Coil in Various Industries
A. Food & Beverage Industry
Tanks, piping, conveyor systems (FDA/USDA compliant)
Brewery equipment, dairy processing
B. Chemical & Pharmaceutical
Storage tanks, heat exchangers (for mild acids)
Bioreactors, cleanroom equipment
C. Architecture & Construction
Facades, railings, roofing (polished or brushed finish)
Elevator panels, decorative trim
D. Automotive & Aerospace
Exhaust systems, fuel lines (304L for welded parts)
Aircraft cabin components
Comparison with Competing Alloys
| Parameter | 304/304L | 316 | 430 (Ferritic) | Duplex 2205 |
|---|---|---|---|---|
| Corrosion Resistance | Good | Excellent (Mo-added) | Moderate | Outstanding |
| Strength (MPa) | 485-515 | 515 | 450 | 620 |
| Cost Factor | $$ | $$$ | $ | $$$$ |
| Weldability | Excellent | Good | Poor | Fair |
| Best For | General-purpose | Marine/chemical | Decorative | High chloride |
In Conclusion
Why Choose 304/304L Stainless Steel Coil?
Most economical austenitic stainless steel for general corrosion resistance.
304L is preferred for welding (no carbide precipitation risk).
Ideal for food, architectural, and chemical applications.
The primary distinction lies in carbon content: 304 contains ≤0.08% carbon, offering optimal strength and formability for general-purpose applications, while 304L reduces carbon to ≤0.03%, significantly mitigating carbide precipitation during welding. This makes 304L ideal for critical welded structures in corrosive environments (e.g., chemical plants, offshore platforms, and food processing equipment), where intergranular corrosion resistance is paramount. Both grades exhibit superior toughness at cryogenic temperatures, aesthetic finish quality (polishable to mirror surfaces), and non-magnetic properties (unless cold-worked). Their versatility extends to deep drawing, bending, and structural fabrication, with 304L additionally prioritizing long-term reliability in welded assemblies.