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Quality Marine Grade 316 Stainless Steel Rectangular Hollow Section Welded ASTM A554 factory
Quality Marine Grade 316 Stainless Steel Rectangular Hollow Section Welded ASTM A554 factory

Marine Grade 316 Stainless Steel Rectangular Hollow Section Welded ASTM A554

Basic Properties
Place of Origin: MADE IN CHAINA
Brand Name: Baosteel，TISCO
Certification: EN 10204 Type 3.1 / 3.2 available
Model Number: 201 / 202 / 301 / 302 / 303 / 304 / 304L / 305 / 309S / 310S / 316 / 316L / 317 / 317L / 321 / 347 / 409L / 410 / 420 / 430 / 440C / 2205 / 2507
Trading Properties
Minimum Order Quantity: 100kg
Price: Negotiable (Request a Quote)
Payment Terms: T/T，D/P，D/A，Western Union，PayPal
Supply Ability: 10000tons
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Molybdenum Alloy Stainless Steel Pipe

Stainless Steel Pipe Chloride Resistance

316 Stainless Steel Rectangular Hollow Section
Product Summary
Marine grade rectangular hollow section (RHS) refers to 316 stainless steel rectangular tubing specifically designed for applications in coastal, offshore, and marine environments where standard 304 stainless steel would be susceptible to pitting and corrosion from chloride exposure. The addition of ...

Product Details

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316 Stainless Steel Rectangular Hollow Section

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Marine Stainless Steel Rectangular Hollow Section

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Rectangular Hollow Section Welded
Country Of Origin: MADE IN CHAINA
Brand: Baosteel，TISCO
Certifications: ISO/EN 10204 Type 3.1 / 3.2 Available
Grade: 201 / 202 / 301 / 302 / 303 / 304 / 304L / 305 / 309S / 310S / 316 / 316L / 317 / 317L / 321 / 347 / 409L / 410 / 420 / 430 / 440C / 2205 / 2507 / 630 (17-4PH)
MOQ: 100kg
Price: Negotiable (Request A Quote)
Packaging: Wooden Case / Wooden Pallet / Steel Frame / Carton / Woven Bag
Delivery Time: 15-25days
Payment Terms: T/T，D/P，D/A，Western Union，PayPal
Supply Capacity: 10000tons
Product Description

Marine grade rectangular hollow section (RHS) refers to 316 stainless steel rectangular tubing specifically designed for applications in coastal, offshore, and marine environments where standard 304 stainless steel would be susceptible to pitting and corrosion from chloride exposure. The addition of 2-3% molybdenum to the 316 grade provides significantly enhanced resistance to pitting, crevice corrosion, and stress corrosion cracking in seawater, salt spray, and chloride-rich atmospheres.

Rectangular hollow sections are manufactured by forming flat stainless steel strip into a rectangular shape and welding the seam longitudinally, followed by solution annealing and pickling or bright annealing to restore corrosion resistance. The result is a structural tube with sharp or rounded corners, available in a wide range of widths, heights, and wall thicknesses to suit various engineering and architectural applications.

Product Specifications
Parameter Details
Product Name Marine Grade Rectangular Hollow Section
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 Marine Grade Rectangular Hollow Section?
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.

Why Choose Marine Grade Rectangular Hollow Section?

 
 
Benefit Explanation
Corrosion Resistance Molybdenum (2-3%) provides chloride resistance for coastal/marine environments
Structural Strength Rectangular shape offers high strength-to-weight ratio
Cost-Effective More affordable than duplex grades for most marine applications
Wide Availability Common sizes in stock
Easy Fabrication Weldable and formable with standard equipment
Low Maintenance No coating or painting required
Long Life 15-25+ years in coastal atmospheres
Aesthetic Options Available in multiple finishes (BA, polished)
Full Traceability Mill test certificates with every shipment

Contact Us

For inquiries, technical data sheets, or a quotation for marine grade rectangular hollow section (316 stainless steel RHS / marine grade rectangular tubing), please contact our sales team.

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