Steel Plate Weight & Dimensions

Quick Reference

Steel plates are flat products >5mm thick (vs. sheets <5mm). Specifications: ASTM A36 (structural), ASTM A516 (pressure vessels), API 2H/2W (offshore), EN 10025 (S235/S275/S355). Manufacturing: hot-rolled or cold-rolled. Applications: shipbuilding, bridges, heavy machinery, pressure vessels, structural framing. Use our steel weight calculator for weight estimation.

Steel Plates Basics

Definition

A steel plate is a broad, flat piece of steel produced in a range of thicknesses for structural and industrial use. Unlike steel sheets, plates are thicker and serve applications that demand higher strength and load-bearing capacity. The threshold between sheet and plate is typically 3/16 inches (about 5 mm); anything above this is classified as plate. Plate dimensions vary widely, from small wear liners up to multi-meter sections for shipbuilding and heavy structural work.

Steel Plate vs. Steel Sheet

The primary difference between steel plates and steel sheets is thickness, which dictates mechanical capability and end use. Both start as steel, but their dimensional ranges target fundamentally different applications.

Steel Sheets

Thickness

Steel plates start at 1/4 inch (about 6.35 mm) and can reach several inches thick. The exact cutoff varies by standard, but 1/4 inch is the most widely accepted boundary. Steel sheets fall below 3/16 inches (about 4.76 mm). Within the sheet category, material thinner than 0.01 inch is typically called “foil,” while the range from 0.01 to 0.25 inch is “sheet.”

Applications

Steel plates go into service where structural strength, pressure containment, or impact resistance matters: buildings, bridges, ship hulls, heavy machinery, and pressure vessels. Steel sheets serve lighter-duty roles (automotive body panels, household appliances, metal roofing, containers, and HVAC ductwork) where formability and surface finish take priority over raw strength.

Manufacturing Process

Both plates and sheets are produced by rolling, either hot or cold. Hot rolling works the steel above its recrystallization temperature, producing a rougher surface but easier cutting and welding. Cold rolling takes hot-rolled stock and processes it further at room temperature, yielding tighter dimensional tolerances, a smoother finish, and increased hardness through work hardening.

Flexibility and Formability

Plates resist bending and require significant force to shape, which is the point; rigidity and durability are the design intent. Sheets are more pliable and respond well to folding, cutting, stamping, and forming into intricate shapes.

Basic Specifications

Steel plate specifications define the material’s properties, dimensions, and quality requirements. They provide the basis for procurement, comparison, and quality verification. The scope of a specification depends on the steel type, its intended service, and the governing standards body.

The key aspects covered in steel plate specifications:

Specification Area	What It Defines
Material Grade	Chemical composition and mechanical properties (strength, ductility, toughness). Different grades target different services, e.g., ASTM A36 for general structural work, ASTM A240 Type 304 for corrosion resistance.
Thickness	Measured in millimeters or inches. Thickness directly governs plate strength and load capacity.
Width and Length	Overall plate dimensions. Stock sizes range from standard mill widths (1200 to 2400 mm) up to several meters for large-scale fabrication.
Mechanical Properties	Tensile strength, yield strength, elongation, and impact resistance, all determined through standardized testing.
Chemical Composition	Allowable concentrations of carbon, manganese, silicon, phosphorus, sulfur, and alloying elements. Chemistry drives both mechanical behavior and corrosion resistance.
Surface Finish	Appearance, texture, and cleanliness requirements. Some services require smooth, scale-free surfaces (cold-rolled or pickled and oiled).
Manufacturing Process	Hot-rolled, cold-rolled, or forged; each process produces different final properties.
Certifications and Standards	Compliance with ASTM, ISO, EN, or industry-specific codes (e.g., ASME for pressure vessels, Lloyd’s Register for marine).
Testing Requirements	Mandatory tests to verify properties: tensile testing, Charpy V-notch impact testing, ultrasonic examination, etc.

Common Material Grades

Steel plates span a wide variety of types, each engineered for specific service conditions. The main differentiators are composition, manufacturing process, and end-use requirements.

1. Carbon Steel Plates

Carbon steel plates are the workhorse of structural and industrial fabrication. They are grouped by carbon content:

Category	Carbon Level	Characteristics	Typical Uses
Low Carbon (Mild Steel)	Up to ~0.25%	Ductile, easy to form and weld	Automotive body panels, buildings, bridges, general infrastructure
Medium Carbon	~0.25 to 0.60%	Balanced strength and ductility	Gears, rails, structural steel components
High Carbon	~0.60 to 1.0%	Hard and strong, reduced ductility	Cutting tools, machinery parts, springs

2. Alloy Steel Plates

Alloy steel plates incorporate elements such as manganese, silicon, nickel, titanium, copper, chromium, and aluminum. These additions boost specific properties (strength, hardness, wear resistance, or corrosion performance) depending on the target application. Common uses include pipelines, automotive components, electrical motors, and construction machinery.

3. Stainless Steel Plates

Stainless steel contains at least 10.5% chromium, which forms a passive oxide layer that resists corrosion. Stainless plates serve chemical processing, food production, pharmaceutical facilities, and marine environments where carbon steel would deteriorate.

4. Tool Steel Plates

Tool steels are formulated for hardness, abrasion resistance, and shape retention at elevated temperatures. They go into drill bits, dies, molds, and hammers, all tooling that must withstand repeated wear and impact.

5. Clad Steel Plates

Clad plates are composites: two or more metals bonded by rolling or explosion welding. A typical configuration pairs a carbon steel base (for strength and economy) with a stainless or nickel alloy face (for corrosion resistance). Pressure vessels, chemical tankers, and refinery equipment are the primary applications.

6. Weathering Steel Plates

Weathering steel (Corten) develops a stable, protective rust patina when exposed to the atmosphere, eliminating the need for paint in many outdoor applications. Bridges, rail cars, and architectural facades where long-term maintenance access is difficult are typical uses.

7. Quenched and Tempered Steel Plates

These plates are heat-treated: heated to austenitizing temperature, rapidly cooled (quenched), then reheated to a moderate temperature (tempered). The result is a plate with high strength and toughness that outperforms standard as-rolled material. Military vehicles, mining equipment, and heavy construction machinery rely on Q&T plates.

ASTM/API/EN Steel Plates Grades

ASTM

ASTM International publishes the most widely referenced standards for steel plates in North America. These standards specify chemical composition, mechanical properties, and manufacturing requirements.

ASTM Standard	Title	Key Characteristics
ASTM A36	Carbon Structural Steel	Good weldability and machinability; can be heat treated to harden the surface; used for structural purposes
ASTM A283	Low and Intermediate Tensile Strength Carbon Steel Plates	Suitable for general structural purposes; grades with varying strength levels
ASTM A285	Pressure Vessel Plates, Carbon Steel, Low- and Intermediate-Tensile Strength	Primarily for pressure vessels; low and intermediate tensile strengths
ASTM A516	Pressure Vessel Plates, Carbon Steel, Moderate- and Lower-Temperature Service	Boilers and pressure vessels; good weldability and excellent notch toughness
ASTM A572	High-Strength Low-Alloy Columbium-Vanadium Structural Steel	Higher strength than A36; improved strength, weldability, and formability
ASTM A588	High-Strength Low-Alloy Structural Steel with Atmospheric Corrosion Resistance	Weathering steel (Corten); atmospheric corrosion resistance; well suited for exposed structures
ASTM A633	Normalized High-Strength Low-Alloy Structural Steel Plates	Welded, riveted, or bolted construction; improved notch toughness
ASTM A656	Hot-Rolled Structural Steel, High-Strength Low-Alloy Plate with Improved Formability	Applications requiring improved formability and weldability
ASTM A710	Precipitation-Strengthened Low-Carbon Ni-Cu-Cr-Mo-Nb Alloy Structural Steel Plates	Weight reduction or increased durability; enhanced atmospheric corrosion resistance
ASTM A829	Alloy Structural Steel Plates	Structural and mechanical applications requiring toughness, strength, and wear resistance

API

The American Petroleum Institute (API) sets standards for the oil and gas sector, where steel plates must withstand aggressive service conditions: saltwater exposure, high pressures, elevated temperatures, and cyclic loading.

API Standard	Title	Key Characteristics
API Spec 2H	Carbon Manganese Steel Plate for Offshore Structures	High-strength, low-alloy plates for welded offshore construction; noted for saltwater corrosion resistance
API Spec 2W	Steel Plates for Offshore Structures (TMCP)	Thermo-Mechanical Control Processed plates; for stationary offshore structures requiring notch toughness testing
API Spec 2Y	Steel Plates, Quenched-and-Tempered, for Offshore Structures	Similar to 2H but quenched and tempered; high strength and toughness for extreme offshore conditions
API Spec 5L	Line Pipe	Covers steel plate material for seamless and welded line pipe; various grades for gas, water, and oil transport under high pressure/temperature
API Spec 12F	Shop Welded Tanks for Storage of Production Liquids	Requirements for small, shop-fabricated, vertical, cylindrical storage tanks for oil; covers steel plate material, design, and testing
API Spec 650	Welded Tanks for Oil Storage	Large welded steel storage tanks; detailed requirements for plate selection, design, fabrication, and inspection

EN/ISO

The EN (European Norm) and ISO standards govern steel plate specifications across Europe and internationally. They cover chemical composition, mechanical properties, dimensions, and fabrication/welding requirements.

Standard	Title	Key Characteristics
EN 10025	Hot rolled products of structural steels	Most commonly referenced for structural steel plates; covers non-alloy, fine-grain, and weather-resistant grades with defined mechanical properties
EN 10028	Flat products made of steel for pressure purposes	Weldable non-alloy and alloy steels with elevated temperature properties; wide range of grades for high pressure/temperature applications
ISO 630	Structural steels - Plates, wide flats, bars, sections and profiles	General-purpose structural steels; six parts detailing chemical composition and mechanical properties
EN 10149	Hot rolled flat products made of high-yield strength steels for cold forming	High-yield strength steels for bending, folding, and cold-forming; covers chemical composition and manufacturing processes
EN 10225	Weldable structural steels for fixed offshore structures	Plates, sections, and tubulars for offshore environments; high resistance to brittle fracture
ISO 15614	Welding procedure specification and qualification	Guidelines for welding procedures for metallic materials; verifies welding meets reliability and safety criteria

Types by Manufacturing Process

Steel plates can also be grouped by how they are made. Each process produces distinct properties suited to different service requirements.

Type	Process	Characteristics	Applications
Hot Rolled	Heating steel slabs and rolling at high temperature above recrystallization temperature	Rough surfaces, loose tolerances; malleable and easy to weld; typically cheaper	Construction, railroad tracks, general fabrication
Cold Rolled	Processing hot rolled plates further by cooling at room temperature and then rolling	Smooth finish, higher strength, tighter tolerances; more brittle and expensive	Automotive parts, appliances, metal furniture, construction
Forged	Shaping metal using localized compressive forces (hammering or pressing) under high pressure	High strength, toughness, wear/impact resistance; fine-grain structure	Machinery parts, tools, high-stress structural integrity applications
Clad	Bonding two or more metals together through rolling or explosion welding	Combines properties of both metals (e.g., strength + corrosion resistance)	Pressure vessels, shipbuilding, pipelines
Quenched & Tempered	Heat treatment: quenching (rapid cooling) then tempering (reheating to lower temperature)	High strength, toughness, wear resistance; less brittle than standard hardened steel	Military vehicles, construction machinery, wear-resistant applications

Difference Steel Plate vs. Rolled Steel Plate

The terms “steel plate” and “rolled steel plates” overlap in practice, but they carry different technical meanings.

Steel Plate is a generic term for any flat steel product thicker than 1/4 inch (6 mm), regardless of manufacturing method. Plates can be cast, forged, or rolled. The term says nothing about how the material was produced, only its geometry.

Rolled Steel Plates specifically identify plates produced by the rolling process, the most common manufacturing route. This category splits into two:

Hot rolled steel plates are produced by passing heated slabs through rollers above the recrystallization temperature. The process yields large plates at lower cost, with a rougher surface and looser tolerances. These are the default choice when precise dimensions are not critical.

Cold rolled steel plates start as hot-rolled stock, then undergo additional rolling at room temperature. This extra processing delivers tighter dimensional tolerances, a smoother surface, and higher strength from work hardening, at a cost premium.

The practical differences come down to three factors:

Factor	Steel Plate (generic)	Rolled Steel Plate
Manufacturing	Any process (cast, forged, rolled)	Specifically produced by hot or cold rolling
Precision and Finish	Varies by production method	Cold-rolled offers tightest tolerances and smoothest surface
Selection Criteria	Depends on application requirements for size, strength, and finish	Chosen when rolling-specific properties (uniformity, surface quality) matter

Weight of Steel Plates

The 3 Dimensions to Consider

The three dimensions of steel plates are:

• Length (in meters or inches/feet)
• Width (in meters or inches/feet)
• Thickness (in millimeters or inches)

steel plates dimensions

These dimensions are used to calculate the weight (in kg. or Lbs.) of steel plates, as explained below.

In a hurry? Calculate the weight of steel plates online using our online calculator!

Weight Calculation Formula

Plates in Metric Sizes

The weight of steel plates is calculated from thickness, width, length, and steel density. The standard formula:

Weight (kgs.) = Thickness × Width × Length × Density of steel

For steel, the density is commonly taken as 7,850 kg/m³ (or 7.85 g/cm³). This value varies slightly with composition and grade (see the grade-specific densities below for carbon steel, stainless steel, alloy steel, and tool steel).

All dimensions (thickness, width, and length) must be in meters to match the density units (kg/m³). If your dimensions are in millimeters, convert to meters first.

Example: a steel plate 10 mm thick (0.01 m) × 1 m wide × 2 m long:

Weight=0.01 m×1 m×2 m×7,850 kg/m3=157 kgWeight=0.01m×1m×2m×7,850kg/m3=157kg

Plates in Imperial Sizes

Steel plates are generally manufactured in standardized widths (36″, 48″, and 60″ the most common) and lengths (96″, 120″, and 144″).

To calculate the weight in Lbs. of a specific imperial steel plate the following formula shall be used:

Weight (Lbs) = Weight (lb/ft2) _ Width (ft) _ Length (ft)

The Weight (lb/ft2) by plate thickness is shown in this table (based on carbon steel material density):

Plate Thickness(in inches)	Weight(lb/ft2)
3/16	7.65
1/4	10.2
5/16	12.8
3/8	15.3
7/16	17.9
1/2	20.4
9/16	22.9
5/8	25.5
11/16	28.1
3/4	30.6
13/16	33.2
7/8	35.7
1	40.8
1 1/8	45.9
1 1/4	51.0
1 3/8	56.1
1 1/2	61.2
1 5/8	66.3
1 3/4	71.4
1 7/8	76.5
2	81.6
2 1/8	86.7
2 1/4	91.8
2 1/2	102
2 3/4	112
3	122
3 1/4	133
3 1/2	143
3 3/4	153
4	163
4 1/4	173
4 1/2	184
5	204
5 1/2	224
6	245
6 1/2	265
7	286
7 1/2	306
8	326
9	367
10	408

Density of Steel by Grade

The density of steel depends on composition and grade but averages around 7,850 kg/m³ (7.85 g/cm³) for most engineering calculations. Alloying elements shift this value slightly.

Carbon Steel

All carbon steel grades (low, medium, and high carbon) share approximately the same density of 7,850 kg/m³. The variation in carbon content has negligible effect on density.

Alloy Steels

Alloy steels incorporate chromium, nickel, molybdenum, silicon, manganese, and vanadium. Because these elements are present in relatively small percentages, density remains close to 7,850 kg/m³ in most alloy grades.

Stainless Steel

Stainless steel density varies more noticeably with alloy family:

Family	Examples	Approximate Density
Austenitic	304, 316	7,900 to 8,000 kg/m³
Ferritic	430	7,700 kg/m³
Martensitic	410	7,750 kg/m³

Tool Steels

Tool steels average around 7,850 kg/m³, comparable to carbon and alloy steels.

Weight Chart for Stock Sizes

Weights of carbon steel plates by thickness/width (metric sizes) are expressed in kilograms per linear meter:

Plate Thickness (mm)	Weight (kg/m2)	kg/meter (width 1200mm)	kg/meter (width 1500mm)	kg/meter (width 1800mm)	kg/meter (width 2400mm)
3	23.55	28.3	35.3	42.4	56.5
4	31.4	37.7	47.1	56.5	75.4
5	39.25	47.1	58.9	70.7	94.2
6	47.1	56.5	70.7	84.8	113
8	62.8	75.4	94.2	113	150.7
10	78.5	94	118	141	188
12	94.2	113	141	170	226
16	125.6	151	188	226	301
20	157	188	236	283	377
22	172.7	207	259	311	415
25	196.25	236	294	353	471
28	219.8	264	330	396	528
32	251.2	301	377	452	603
36	282.6	339	424	509	678
40	314	377	471	565	754
45	353.25	424	530	636	848
50	392.5	471	589	707	942
55	431.75	518	648	777	1036
60	471	565	707	848	1130
65	510	612	765	918	1224
70	549.5	659	824	989	1319
75	588.75	707	883	1060	1413
80	628	754	942	1130	1507
90	706.5	848	1060	1272	1696
100	785	942	1178	1413	1884

Pro Tip

When ordering A516 Gr.70 plates for pressure vessels, always specify normalized heat treatment for thicknesses above 1.5” (38mm). Thicker plates without normalizing may have reduced impact toughness at the center - the as-rolled condition doesn’t guarantee uniform properties through the thickness.

Common Mistake

Accepting mill certificates that show “A36/A572-50 dual certified” without verifying the actual properties meet your design requirements. Dual-certified means the plate passed both specs’ minimum requirements, but the actual yield strength could be anywhere between A36’s 36 ksi and A572-50’s 50 ksi. If your design relies on specific strength, specify and verify.

Field Note

Before cutting or welding weathering steel (Corten), remove the rust-colored patina from the weld zone. That protective layer contains moisture and contaminants that cause porosity and hydrogen cracking in welds. Grind back to bright metal, weld, then let the patina re-form naturally.