ASTM A36
Basic Info
The ASTM A36 standard specifies a standard specification for ordinary carbon structural steel, suitable for construction, manufacturing, bridges, and other structures.
Characteristics
High Strength: ASTM A36 steel has a minimum tensile strength of 400 MPa and a minimum yield strength of 250 MPa, making it suitable for structural applications where strength is crucial.
Good Ductility: It offers good ductility and can be bent, formed, and welded without compromising its properties. This makes it versatile for various fabrication processes.
Weldability: ASTM A36 steel is well-known for its excellent weldability, allowing for easy welding, joining, and fabrication into complex structures without the need for preheating.
Machinability: This steel has good machinability, meaning it can be easily cut, drilled, machined, and shaped using common tools and techniques.
ASTM A36 Data Sheet
Equivalent Steel Grades
ASTM A36 vs. ASTM A572
Specification
Chemical Composition
Mechanical Properties
Fabrication and Welding
Equivalent Steel Grades
United States
- Equivalent Grade: ASTM A283 Grade D
- Standard: ASTM A283/A283M
- Notes: Low and Intermediate Tensile Strength Carbon Steel Plates
European Union
- Equivalent Grade: S235JR
- Standard: EN 10025-2
- Notes: Non-alloy structural steel
China
- Equivalent Grade: Q235B
- Standard: GB/T 700-2006
- Notes: Carbon structural steel
India
- Equivalent Grade: IS 2062 Grade B
- Standard: IS 2062:2011
- Notes: Hot Rolled Medium and High Tensile Structural Steel
ASTM A36 vs. ASTM A572
Chemical Composition:
- ASTM A36: Contains 0.25% max Carbon, 0.80-1.20% Manganese, 0.04% max Phosphorus, 0.05% max Sulfur, and 0.40% max Silicon.
- ASTM A572 Grade 50: Contains 0.23-0.26% Carbon, 1.35% Manganese, 0.04% max Phosphorus, 0.05% max Sulfur, and 0.15-0.40% Silicon.
- Notes: Both steels have similar Carbon content, but A572 has higher Manganese content and a wider range of Silicon content.
Tensile Strength:
- ASTM A36: 400-550 MPa min.
- ASTM A572 Grade 50: 450 MPa min.
- Notes: A572 has higher tensile strength.
Yield Strength:
- ASTM A36: 250 MPa min.
- ASTM A572 Grade 50: 345 MPa min.
- Notes: A572 has higher yield strength.
Elongation:
- ASTM A36: 20% min (in 200mm), 23% min (in 50mm).
- ASTM A572 Grade 50: 18% min (in 200mm), 21% min (in 50mm).
- Notes: A36 has slightly higher elongation.
Modulus of Elasticity:
- Both ASTM A36 and ASTM A572 Grade 50: 200 GPa and 190-210 GPa, respectively.
- Notes: Both have similar modulus of elasticity.
Charpy V-Notch Impact:
- ASTM A36: No specified requirement.
- ASTM A572 Grade 50: 20-30 J (15-22 ft-lb) impact resistance.
Applications:
- ASTM A36: Used for construction, machinery, and equipment.
- ASTM A572 Grade 50: Used for structural steel in welded construction.
- Notes: A36 is for general construction, machinery, and equipment, while A572 Grade 50 is for high-strength, low-alloy structural steel.
Specification
Plates:
- Dimensions (Width x Thickness): Various widths x Thicknesses
- Tolerances:
- Width: +0/- Tolerance
- Thickness: +0.125/-0.000 inch
- Notes:
- Width tolerance applies to plate lengths not exceeding 96 inches (2438 mm).
- Thickness tolerance applies to plates between 3/16 and 10 inches (4.76 – 254 mm) thick.
Bars:
Round: Diameter up to 20 inches
- Tolerances: Diameter: +0/- Tolerance
- Notes: Diameter tolerance applies to round bars. Thickness: +0.0625/-0.000 inch
Square: Side up to 8 inches
- Tolerances: Side: +0/- Tolerance
- Notes: Side tolerance applies to square bars. Thickness tolerance applies to rectangular bars.
Rectangular: Thickness up to 6 inches
- Tolerances: Length: ±1/8 inch
- Notes: Length tolerance applies to rectangular bars. Thickness tolerance applies to rectangular bars.
Structural Shapes:
- Dimensions (Various dimensions):
- Tolerances:
- Dimensional: ±1.5% of specified depth or width
- Flange Thickness: +0.0625/-0.0625 inch
- Web Thickness: +0.0625/-0.0625 inch
- Notes: Applies to I-Beams, Channels, and Angles.
- Tolerances:
Steel Plates:
- Dimensions (Width x Thickness): Various widths x Thicknesses
- Tolerances:
- Width: +0.125/-0 inch
- Thickness: +0.010/-0.010 inch
- Notes:
- Width tolerance applies to plate lengths not exceeding 96 inches (2438 mm).
- Thickness tolerance applies to plates between 3/16 and 10 inches (4.76 – 254 mm)
Chemical Composition
Carbon (C): Maximum 0.25%
Manganese (Mn): 0.80 – 1.20%
Phosphorus (P): Maximum 0.04%
Sulfur (S): Maximum 0.05%
Silicon (Si): Maximum 0.40%
Mechanical Properties
Tensile Strength: 400 – 550 MPa (58,000 – 80,000 psi)
Yield Strength: 250 MPa min (36,000 psi)
Elongation: 20% min (in 200 mm) / 20% min (in 8 inches)
23% min (in 50 mm): 23% min (in 2 inches)
Modulus of Elasticity: 200 GPa (29,000,000 psi)
Poisson’s Ratio: 0.26 (same for metric and imperial)
Shear Modulus: 79.3 GPa (11,500,000 psi)
Bulk Modulus: 160 GPa (23,200,000 psi)
Fabrication and Welding
Cutting:
Flame Cutting
- Guidelines: Use oxy-acetylene torches, plasma, or laser cutting. Preheat is not required for thicknesses up to 1 inch (25 mm).
- Notes: Preheating may be required for thicker sections.
Sawing
- Guidelines: Use high-speed steel blades. Coolant is recommended during cutting.
- Notes: Not required for thinner sections.
Shearing
- Guidelines: Use appropriate shear blades.
- Notes: No specific notes provided.
Machining
- Guidelines: Use carbide tooling and appropriate cutting speeds.
- Notes: No specific notes provided.
Forming:
Cold Forming
- Guidelines: Bend along the grain direction. Avoid sharp bends and use a minimum bend radius of 3 times the material thickness.
- Notes: Ensure proper cooling after hot forming to avoid distortion.
Hot Forming
- Guidelines: Heat to 1600°F – 1200°F (870°C – 650°C) and then air or oil quench.
- Notes: Ensure proper cooling after hot forming to avoid distortion.
Welding:
Shielded Metal Arc Welding (SMAW)
- Guidelines: Use AWS E70B electrodes.
- Notes: Preheat is not usually required for thicknesses up to 1 inch (25 mm).
Gas Metal Arc Welding (GMAW/MIG)
- Guidelines: Use E70S-3 or E70S-6 electrodes.
- Notes: Preheat is not usually required for thicknesses up to 1 inch (25 mm).
Flux-Cored Arc Welding (FCAW)
- Guidelines: Use E71T-1 or E71T-11 electrodes.
- Notes: Preheat is not usually required for thicknesses up to 1 inch (25 mm).
Gas Tungsten Arc Welding (GTAW/TIG)
- Guidelines: Use AWS E70B filler rod.
- Notes: Preheat is not usually required for thicknesses up to 1 inch (25 mm).
Post-Weld Heat Treatment (PWHT)
- Guidelines: Typically not required for structural applications.
- Notes: No specific notes provided.
Interpass Temperature
- Guidelines: Maintain within 250°F – 450°F (121°C – 232°C).
- Notes: For thicknesses over 1 inch (25 mm), preheat may be required depending on section size.
Preheat
- Guidelines: Not usually required for thicknesses up to 1 inch (25 mm).
- Notes: Preheat may be required for thicker sections.
Back Gouging
- Guidelines: For full penetration welds, back gouge and remove slag inclusions.
- Notes: No specific notes provided.
Electrode Selection
- Guidelines: Choose electrodes based on mechanical properties and application.
- Notes: No specific notes provided.
Welding Procedures and Parameters
- Guidelines: Follow recommended parameters from welding codes (e.g., AWS D1.1).
- Notes: No specific notes provided.
