Medium- and heavy-gauge plates refer to steel plates with a thickness of 4.5–25.0 mm; those with a thickness of 25.0–100.0 mm are called heavy-gauge plates, and those exceeding 100.0 mm in thickness are classified as extra-heavy-gauge plates.
Specifications for Medium- and Heavy-Gauge Plates
I. Standard Medium- and Heavy-Gauge Plates:
Low-alloy structural steel plates (GB 3274-88)
Low-alloy structural steel plates are produced by hot-rolling low-alloy structural steel. These plates are classified as killed steel or semi-killed steel. Their advantages include high strength, superior performance, significant material savings, and reduced structural weight.
Weathering Steel Plates for Welded Structures (GB4172-84)
Weathering steel refers to steel resistant to atmospheric corrosion. Weathering steel for welded structures is produced by adding small amounts of alloying elements—such as manganese, chromium, nickel, molybdenum, niobium, titanium, zirconium, and vanadium—to the steel. This creates a protective layer on the surface of the metal matrix, enhancing the steel’s weather resistance and ensuring good weldability.
High Weather-Resistant Structural Steel Plates (GB4171-84)
Weather-resistant steel refers to steel resistant to atmospheric corrosion. By adding small amounts of alloying elements—such as iron, phosphorus, chromium, nickel, molybdenum, niobium, titanium, zirconium, and vanadium—to the steel, a protective layer forms on the surface of the metal matrix, thereby enhancing the steel’s weather resistance.
Patterned Steel Plates (GB3277-82)
Patterned steel plates are steel plates with diamond-shaped or lentil-shaped raised ribs on their surface. Their specifications are indicated by their thickness (excluding the thickness of the raised ribs).
High-Quality Medium and Heavy Plates:
High-Quality Carbon Structural Steel Hot-Rolled Medium and Heavy Plates (GB711-88)
High-quality carbon structural steel hot-rolled medium and heavy plates, commonly referred to as high-quality carbon structural steel heavy plates, are made of high-quality carbon structural steel and produced through hot rolling. They may also be supplied in normalized, annealed, or tempered conditions.
High-quality carbon hot-rolled heavy plates for automobile manufacturing (GB3275-82)
High-quality carbon structural steel hot-rolled thick plates for automotive manufacturing are made from high-quality carbon structural steel and produced through hot rolling. Depending on the production methods and processing depth, they are classified into three categories: deep drawing (S), general drawing (P), and cold bending (W).
Carbon Tool Steel Thick Plates (GB3278-82)
Carbon tool steel thick plates are made from carbon tool steel and produced through hot rolling. These plates offer good cold and hot working properties, high hardness and ductility, low production costs, and a wide range of applications. Their main drawbacks are poor heat resistance and poor hardenability; they are generally supplied in an annealed or high-temperature tempered condition.
Alloy Structural Steel Thick Plates (GB11251-89)
Alloy structural steel thick plates are made from alloy structural steel and produced by hot rolling.
Classification of Medium- and Heavy-Gauge Steel Plates by Production Process
1. Hot-Rolled Medium- and Heavy-Gauge Steel Plates: Hot-rolled medium- and heavy-gauge steel plates are produced through a high-temperature hot-rolling process. They are characterized by a relatively smooth surface and high hardness, and are widely used in various fields such as machinery manufacturing, building structures, and container manufacturing.
2. Cold-Rolled Medium and Heavy Plates: Cold-rolled medium and heavy plates are produced using a low-temperature cold-rolling process. They feature excellent surface quality and precise dimensions, and are widely used in automotive manufacturing, electrical appliance manufacturing, refrigeration equipment, and marine engineering.
Applications of Medium and Heavy Plates
Medium and heavy plates are primarily used in construction engineering, machinery manufacturing, container manufacturing, shipbuilding, and bridge construction. They can also be used to manufacture various containers, furnace shells, furnace plates, bridges, as well as automotive structural steel plates, low-alloy steel plates, shipbuilding steel plates, boiler steel plates, pressure vessel steel plates, checkered steel plates, automotive chassis steel plates, certain tractor parts, and welded components.
1. Structural Medium- and Heavy-Gauge Steel Plates: Structural medium- and heavy-gauge steel plates are used in construction, bridges, mechanical equipment, highways, wind power, and other fields. They are characterized by high strength, good corrosion resistance, weldability, and ease of processing.
2. Oil and Gas Medium- and Heavy-Gauge Steel Plates: Oil and gas medium- and heavy-gauge steel plates are used in oil and gas pipelines, underground storage tanks, gas purification equipment, and other fields. They are characterized by high-temperature resistance, corrosion resistance, and good resistance to hydrogen embrittlement.
3. Medium- and thick-gauge plates for shipbuilding: These plates are used in shipbuilding, offshore engineering, and port facilities. They feature high strength and corrosion resistance, capable of withstanding rough seas and seawater erosion.
Classification of medium- and thick-gauge plates by surface condition
1. Hot-rolled black plates: These have a smooth surface without any coating or finishing and are typically used in welding and fabrication.
2. Hot-rolled pickled plate: Medium- and heavy-gauge plates treated through a pickling process, featuring a flat, smooth surface and excellent corrosion resistance.
3. Galvanized plate: A layer of zinc is applied to the surface of black plate or pickled plate to enhance corrosion resistance and extend the service life of the medium- and heavy-gauge plates.
Characteristics of Medium- and Heavy-Gauge Steel Plates
First, they offer excellent resistance to impact and vibration. Incorporating these plates into buildings and bridges significantly enhances vibration resistance, greatly improving safety.
Second, because they are much thinner than standard steel plates, medium-thickness plates do not offer outstanding corrosion resistance and are rarely used in industries such as petrochemicals.
Third, they possess good load-bearing capacity and excellent performance. In applications such as bridges, automotive chassis beams, and buildings—where strict requirements for steel load-bearing capacity exist—failure to meet these standards can easily lead to accidents, making the selection of steel materials particularly demanding.
Specifications and Dimensions of Medium- and Heavy-Gauge Steel Plates
1. Common Specifications
Common specifications for medium- and heavy-gauge steel plates include 4×2000×6000 mm, 5×1500×6000 mm, 6×1800×6000 mm, and others.
2. Common Thicknesses
Common thicknesses for medium and heavy plates include 4 mm, 5 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, and 60 mm. Common widths for medium- and heavy-gauge plates are 1500 mm, 1800 mm, and 2000 mm, while common lengths are 6000 mm, 8000 mm, and 12000 mm.
How to Select Medium- and Heavy-Gauge Steel Plates
The selection of medium- and heavy-gauge steel plates should be based on specific application needs and specification requirements. Factors to consider include plate thickness, width, length, material, and surface treatment. During the selection process, factors such as cost, durability, and safety should also be taken into account, and a decision should be made after comprehensive consideration.
Post time: Mar-07-2026
