316 stainless steel rectangular tubing is the premium choice for applications requiring superior
corrosion resistance, especially in chloride-rich environments such
as coastal areas, marine settings, and chemical processing
facilities. The addition of molybdenum (2-3%) gives 316
significantly better resistance to pitting, crevice corrosion, and
stress corrosion cracking compared to 304 stainless steel.
This rectangular hollow section (RHS) is manufactured to ASTM A554
standard, specifically designed for mechanical and structural
applications where both strength and aesthetics matter. Available
in a wide range of sizes and surface finishes — from industrial
mill finish to decorative No.4 brushed and No.8 mirror polish — 316
rectangular tubing delivers reliable performance in demanding
environments.
Product Specifications
| Parameter | Details |
|---|
| Product Name | 316 Stainless Steel Rectangular Tubing |
| Standard | ASTM A554 (MT-316 / MT-316L) |
| Equivalent Standards | EN 10219 (1.4401/1.4404), JIS G3446 (SUS316), GB/T 12770 |
| Construction | Welded (ERW – Electric Resistance Welded) |
| Outer Dimensions (A * B) | 10mm * 5mm to 200mm * 100mm (0.39″ * 0.20″ to 7.87″ * 3.94″) |
| Wall Thickness | 0.5mm – 5.0mm (0.020″ – 0.197″) |
| Length | 3m – 6m (standard); up to 12m (custom) |
| Surface Finish | Mill Finish, Pickled, No.4 Brushed, No.8 Mirror Polished |
| Corner Radius | 1.5 * WT maximum |
Chemical Composition (ASTM A554 MT-316 / MT-316L)
| Element | MT-316 (%) | MT-316L (%) | Requirement |
|---|
| Carbon (C) | ≤0.08 | ≤0.030 | Low carbon for better weldability |
| Manganese (Mn) | ≤2.00 | ≤2.00 | – |
| Silicon (Si) | ≤1.00 | ≤1.00 | – |
| Chromium (Cr) | 16.0 – 18.0 | 16.0 – 18.0 | Provides corrosion resistance |
| Nickel (Ni) | 10.0 – 14.0 | 10.0 – 14.0 | Enhances ductility and toughness |
| Molybdenum (Mo) | 2.0 – 3.0 | 2.0 – 3.0 | Key element for chloride resistance |
| Phosphorus (P) | ≤0.045 | ≤0.045 | – |
| Sulfur (S) | ≤0.030 | ≤0.030 | – |
| Iron (Fe) | Balance | Balance | – |
Key Difference Between 316 and 304:
- 316 contains 2-3% Molybdenum
- 304 contains 0% Molybdenum
- This single element dramatically improves chloride resistance
Mechanical Properties (ASTM A554)
| Property | MT-316 | MT-316L |
|---|
| Tensile Strength | ≥515 MPa (75 KSI) | ≥485 MPa (70 KSI) |
| Yield Strength (0.2%) | ≥205 MPa (30 KSI) | ≥170 MPa (25 KSI) |
| Elongation | ≥35% | ≥35% |
| Hardness (HRB) | ≤95 | ≤95 |
| Hardness (HB) | ≤217 | ≤217 |
Typical Values (Annealed Condition):
- Elastic Modulus: 193 GPa (28,000 KSI)
- Shear Modulus: 77 GPa (11,200 KSI)
- Poisson's Ratio: 0.30
- Density: 7.98 g/cm³ (0.288 lb/in³)
Physical Properties
| Property | Value |
|---|
| Density | 7.98 g/cm³ |
| Melting Range | 1370 – 1400°C (2500 – 2550°F) |
| Specific Heat (0-100°C) | 500 J/kg·K |
| Thermal Conductivity (100°C) | 16.3 W/m·K |
| Thermal Expansion (20-100°C) | 17.2 * 10⁻⁶ /°C |
| Electrical Resistivity (20°C) | 74 μΩ·cm |
| Magnetic Permeability | 1.02 (annealed, essentially non-magnetic) |
Corrosion Resistance – Why Choose 316 Stainless Steel Rectangular
Tubing?
| Environment | 304 Performance | 316 Performance |
|---|
| Coastal / Salt Spray | Moderate (pitting possible) | Excellent |
| Marine (Seawater) | Poor (rapid pitting) | Good to Excellent |
| Chloride Solutions | Poor (SCC risk) | Good |
| Acids (Sulfuric, dilute) | Poor | Fair to Good |
| Acids (Phosphoric) | Fair | Good |
| Food / Beverage | Excellent | Excellent |
| Pharmaceutical | Excellent | Excellent |
| Outdoor (Industrial) | Good | Excellent |
Key Corrosion Metrics:
| Metric | 304 | 316 |
|---|
| PREN Value* | 18-20 | 24-26 |
| Critical Pitting Temperature | ~20°C | ~35°C |
| SCC Resistance in Chlorides | Low | High |
*PREN = Pitting Resistance Equivalent Number (Cr + 3.3Mo + 16N)*
Bottom Line: If your application involves saltwater, coastal exposure,
de-icing salts, or chemical contact — choose 316.
Standard Dimensions & Sizes
Small Sizes (10mm – 50mm)
| A * B (mm) | Wall Thickness (mm) | Weight (kg/m) | Typical Use |
|---|
| 10 * 5 | 0.5, 0.8 | 0.22 – 0.35 | Small frames, marine hardware |
| 15 * 10 | 0.8, 1.0, 1.2 | 0.47 – 0.69 | Boat railings |
| 20 * 10 | 0.8, 1.0, 1.2, 1.5 | 0.55 – 0.99 | Coastal furniture |
| 20 * 15 | 1.0, 1.2, 1.5 | 0.69 – 1.03 | Marine frames |
| 25 * 15 | 1.0, 1.2, 1.5, 2.0 | 0.85 – 1.35 | Handrails (coastal) |
| 25 * 25 | 1.0, 1.2, 1.5, 2.0 | 1.03 – 1.59 | Square – marine structures |
| 30 * 20 | 1.2, 1.5, 2.0 | 1.29 – 2.07 | Boat frames |
| 40 * 20 | 1.5, 2.0, 2.5 | 1.83 – 2.98 | Marine equipment |
| 40 * 40 | 1.5, 2.0, 2.5 | 2.50 – 3.98 | Square – coastal structures |
| 50 * 25 | 1.5, 2.0, 2.5 | 2.18 – 3.50 | Trailer frames (coastal) |
| 50 * 50 | 1.5, 2.0, 2.5, 3.0 | 3.16 – 5.05 | Square – marine columns |
Medium to Large Sizes (60mm – 200mm)
| A * B (mm) | Wall Thickness (mm) | Weight (kg/m) | Typical Use |
|---|
| 60 * 40 | 2.0, 2.5, 3.0 | 3.70 – 5.45 | Offshore structures |
| 60 * 60 | 2.0, 2.5, 3.0 | 4.31 – 6.32 | Square – marine frames |
| 80 * 40 | 2.0, 2.5, 3.0 | 4.15 – 6.11 | Chemical plant supports |
| 80 * 60 | 2.5, 3.0, 4.0 | 5.89 – 8.99 | Heavy marine |
| 80 * 80 | 2.5, 3.0, 4.0 | 7.08 – 10.74 | Square – offshore |
| 100 * 40 | 2.5, 3.0, 4.0 | 6.16 – 9.53 | Chemical piping supports |
| 100 * 50 | 2.5, 3.0, 4.0 | 6.52 – 10.08 | Marine platforms |
| 100 * 80 | 3.0, 4.0, 5.0 | 9.52 – 15.18 | Heavy marine structures |
| 100 * 100 | 3.0, 4.0, 5.0 | 10.75 – 16.98 | Square – offshore columns |
| 120 * 60 | 3.0, 4.0, 5.0 | 9.92 – 15.82 | Desalination plant frames |
| 150 * 100 | 4.0, 5.0 | 18.53 – 22.50 | Heavy chemical structures |
| 200 * 100 | 4.0, 5.0 | 22.82 – 28.05 | Large marine structures |
Custom dimensions available upon request
Dimensional Tolerances (ASTM A554)
| Parameter | Tolerance |
|---|
| Outside Dimensions (A & B) | ±0.5% (min ±0.3mm, max ±1.5mm) |
| Wall Thickness | ±10% |
| Length (fixed) | +3mm / -0mm |
| Twist | ≤0.5mm per meter * width/100 |
| Concave/Convex | ≤0.4mm per side |
| Corner Radius | ≤1.5 * WT |
| Straightness | ≤1.0mm per meter |
Surface Finishes for 316 Tubing
| Finish | Code | Description | Ra (μm) | Best For |
|---|
| Mill Finish | – | As-welded, light scale | 2.0-3.0 | Industrial, hidden marine structures |
| Pickled | No.1 | Acid cleaned, matte | 1.5-2.5 | Chemical plants, welding prep |
| Brushed (Hairline) | No.4 | 150-180 grit brushed | 0.4-0.8 | Marine handrails, coastal railings |
| Mirror Polished | No.8 | Highly reflective | 0.1-0.2 | Architectural marine, luxury yachts |
| Satin | 320-400 grit | Fine matte | 0.3-0.5 | Food processing, pharmaceutical |
Recommendation for Marine Applications: No.4 Brushed finish provides the best balance of corrosion
resistance and aesthetics. The brushed surface hides minor
scratches and salt spray marks.
Contact Us
Need 316 for a coastal or marine project? Send your 316 Stainless
Steel Rectangular Tubing specifications to us — we will reply
within 24 hours with pricing and MTC.
ASTM A554 304 316 Stainless Steel Rectangular Tube Welded For Furniture Frames Mill
