This specification covers medium-thickness steel plates compliant with ASTM (American Society for Testing and Materials) standards. It is a widely used size for structural, mechanical, and engineering applications.
1. Basic Dimensions & Weight
Thickness: 20mm (Approx. 0.787 inches)
Width: 2200mm (Approx. 86.6 inches)
Length: Customizable (L). Standard lengths: 6000mm, 12000mm.
Theoretical Weight:
Per Meter: ~345.4 kg/m (Formula:20mm×2200mm×1m×7.85g/cm3÷100020mm×2200mm×1m×7.85g/cm3÷1000)
Per Square Meter: ~157 kg/m ² (20mm×7.85g/cm320mm×7.85g/cm3)
2. Common ASTM Material Grades
| Standard | Material Type | Characteristics & Key Uses |
| ASTM A36 | Carbon Structural Steel | Most common; comparable to Q235B; used for general structural parts. |
| ASTM A572 Gr.50 | HSLA Steel | High-strength low-alloy; excellent toughness for bridges and buildings. |
| ASTM A992 | Structural Steel | Primarily for high-rise buildings; excellent weldability. |
| ASTM A588 | Weathering Steel | Atmospheric corrosion resistance; suitable for unpainted outdoor structures. |
| ASTM A516 Gr.60/70 | Pressure Vessel Steel | Exceptional notch toughness; used for boilers and pressure vessels. |
3. Core Application Scenarios
I. Construction and Bridge Structures
High-Rise Buildings: Beams, columns, and bracing. The 2200mm width reduces welding seams, improving structural integrity.
Bridges: Deck plates and pier connection components, typically using high-strength A572 Gr.50.
Industrial Plants: Support columns and crossbeams for large-span steel structures.
II. Machinery and Equipment Manufacturing
Bases & Frames: Heavy equipment bases and worktables where 20mm thickness provides stability and deformation resistance.
Construction Machinery: Chassis and counterweights for excavators and cranes. Wide plates allow for direct cutting, reducing processing steps.
Tooling & Dies: Mold bases and jigs using easily machinable A36 steel.
III. Shipbuilding and Offshore Engineering
Hull & Deck: Structural plating for ships and local reinforcement zones.
Offshore Platforms: Support structures and railing frames. ASTM A588 (weathering) is often chosen to resist marine corrosion.
Port Machinery: Load-bearing components for cranes and loading equipment.
IV. Pressure Vessels and Chemical Equipment
Shells & Heads: Liners and shells for low-to-medium pressure vessels (using ASTM A285 or A516).
Storage Tanks: Tank walls and bottom reinforcement. Wider plates minimize weld lines, reducing the risk of corrosion and leakage.
V. Specialized Engineering
Wind Power: Flanges and base reinforcement plates for wind towers.
Vehicle Modification: Chassis frames and protective plating for heavy-duty or specialized trucks.
Temporary Works: Heavy-duty construction platforms and hoarding.
4. Technical Performance Parameters (ASTM A6/A6M)
Mechanical Properties Comparison
| Grade | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) | Key Features |
| A36 | ≥ 250 (36 ksi) | 400–550 (58–80 ksi) | ≥ 20% | Cost-effective, excellent weldability. |
| A572 Gr.50 | ≥ 345 (50 ksi) | 448–586 (65–85 ksi) | ≥ 18–20% | High strength, contains Columbium-Vanadium. |
| A588 Gr.B | ≥ 345 (50 ksi) | ≥ 485 (70 ksi) | ≥ 18% | Atmospheric corrosion resistance. |
| A516 Gr.60 | ≥ 240 (35 ksi) | 415–550 (60–80 ksi) | ≥ 21% | Excellent notch toughness for vessels. |
Dimensional Tolerances (per ASTM A6)
Thickness Tolerance: +1.55mm / -0mm (for 20≤T<25)
Width Tolerance: +11mm / -0mm (for 2100≤W<2700)
Length Tolerance: +15mm / -0mm (for length≤6000mm)
5. Surface Quality & Processing
Delivery State: Usually Hot Rolled (HR).
Surface Finish:
Black/As-rolled: Unprocessed mill scale.
Shot Blasting: Sa2.5 grade (clean surface, roughness 40–60μm).
Coating: Galvanized (30–275g/m²) or Oil-protected.
Weldability:
A36/A572: Excellent; generally requires no preheating for 20mm thickness at room temperature.
Cold Bending: Minimum bend radius is typically 1.5 times the plate thickness (1.5×20mm=30mm).
6. Market & Purchasing Reference (Estimated Nov. 2025)
ASTM A36: Approx. 309–499 USD / Ton (MOQ: 10 Tons).
HSLA (A572/A588): Approx. 525–800 USD / Ton (MOQ: 1 Ton).
Supply: Readily available from major global mills; typically delivered in hot-rolled condition.
Selection Summary:
General Structures: Choose A36 for the best cost-to-performance ratio.
High-Load/Bridges: Choose A572 Gr.50 for superior strength and seismic resistance.
Outdoor/Marine: Choose A588 for maintenance-free longevity.
Safety Critical/Tanks: Choose A516 Gr.60 for guaranteed toughness.
