Q345B/C/D/E – ASTM A6 Low Alloy Steel Plate Carbon Steel Coil Industrial Material

Mechanical Properities
thickness test  temperature
proof stress
Tensile strenth
Q345A ≤16  – 21 345 470-630
Q345B ≤16  20 21 345 470-630
Q345C 16-35 0 22  ≥325 470-630
Q345D 35-50 -20 22  ≥295 470-630
Q345E 50-100 -40 22 ≥275 470-630

Product Introduction

Q345 is a commonly used low alloy structural steel in China. Its chemical composition and mechanical properties are regulated by the Chinese national standard GB/T1591-2008.  

Q345 low alloy steel is equivalent to ASTM A6 in the United States. Q345A/B/C carbon content generally does not exceed 0.20%. Q345D/E carbon content generally does not exceed 0.18%.

Q345A, Q345B, Q345C, Q345D, Q345E These are the distinction between grades, and what it represents is mainly the difference in the temperature of the impact!

Q345 has the following general characteristics:

1)Low alloy, low carbon Content: Q345 steel belongs to the category of low alloy  structural steel, cold extruded, carburized and hardened steel. The carbon content in Q345 is generally less than 0.20%, making it a low carbon alloy steel suitable for welding and forming processes.

2)Good Weldability: Q345 steel can be easily welded using common welding methods such as arc welding, resistance welding, and gas welding.

3)Good comprehensive properties: good low temperature properties, good cold stamping properties, good welding properties and machinability.

4)Excellent Plasticity: Q345 steel exhibits good plasticity, allowing it to be formed into various shapes and structures without fracturing.

5)Wide Application: Q345 steel is widely used in general structural and engineering purposes, including construction, bridges, machinery manufacturing, pressure vessels, transportation equipment, and other industries where strength and durability are required.

  Alloy plate is a plate composed of a mixture of different metal elements, which has excellent physical and chemical properties.Its short description can be: a sheet made of a mixture of multiple metals, with high strength, corrosion resistance and excellent thermal conductivity, widely used in industry, construction and aerospace and other fields.
Product NameAlloy Carbon Steel Plates
TechniqueHot/Cold Rolled
SurfaceBlack Painted, Galvanized, Color Coated, Et
Price TermEx-Work, Fob, CFR, CIF,TT,L/C
Transport PackageStandard Shipping Packaging
Grade & Element & Chemical Composition(%)
Q345 Steel Equivalent Standard(ASTM/EN/JIS):
Steel for boiler and other pressure vesselsGB 713-2008
ASTM A537-08
JIS G3115
Q245R (20g/20R); Q345R (16Mng/16MnR)
Class 1/2/3
SPV235; SPV315; SPV355
High strength low alloy structural steelGB/T 1591-2008
EN 10028-3-2003
EN 10025-2004
ASTM A572-07
ASTM A588-05
Q345 (A/B/C/D/E); Q390; Q420
Grade 50; Grade 60
Grade A; Grade B


Q345 steel has a wide range of applications in various industries due to its good comprehensive properties and affordability. Some common applications of Q345 steel plate include:

1)Construction: Q345 steel is extensively used in the construction industry for various structural components, such as beams, columns, and frameworks. It is suitable for both residential and commercial construction projects.

2)Bridges: Q345 steel is commonly used for bridge construction, including the fabrication of bridge girders, piers, and structural supports. Its high strength and good weldability make it suitable for bridge applications.

3)Machinery Manufacturing: Q345 steel is employed in the manufacturing of machinery and equipment components, such as frames, chassis, and structural parts. Its versatility and easy machinability make it a preferred choice for various machinery applications.

4)Automotive Industry: Q345 steel is utilized in the automotive industry for the production of components like car frames, chassis, and structural parts. Its high strength and good formability make it suitable for automotive applications.

5)Railway Vehicles: Q345 steel is also used in the manufacturing of railway vehicles, including railcar bodies, underframes, and structural components. Its mechanical properties and durability meet the requirements of the railway industry.

6)Storage Tanks: Q345 steel is sometimes employed in the construction of storage tanks for storing liquids or gases. Its weldability and strength make it suitable for this application.

7)General Fabrication: Q345 steel is widely utilized in general fabrication processes where a low alloy carbon steel with good mechanical properties is required. It can be formed, welded, and machined to create various structures and components.

Classification By Size:

The length is generally 2440mm, 2000mm, 3050mm, 4000mm, 3000mm, and the thickness is distinguished by cold rolling and hot rolling. Cold rolling mainly has thickness 1.0mm, 1.2mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm. The main thickness of hot rolling is 3.0mm, 4.0mm, 6.0mm, 8.0mm, 10.0mm, and the width is generally 1000mm, 1219mm, 1500mm.Please contact customer service for general specifications.

Hot-rolled products have excellent properties such as high strength, good toughness, easy processing and good weldability, so they are widely used in manufacturing industries such as steel, construction, machinery, boilers, and pressure vessels. Application range: (1) After annealing, it is processed into ordinary cold rolling; (2) The galvanizing unit with pre-annealing treatment device processes galvanizing; (3) Panels that basically do not need to be processed.

Hot-rolled coils (in the form of flat plates or coils) generally have a thickness of 2.0-13.5mm, of which the price of 2.0-3.0mm hot coils gradually decreases from thin to thick; most steel mills have a basic price of 3.1mm-13.5mm Equivalent, the price of 3.1-4.0mm and 9.5mm-13.5mm hot plate coils in some manufacturers and markets may be higher than the price of 4.0mm-9.5mm plates. Hot plate coils represent products with a thickness of 5.5mm. Under normal circumstances, the price of flat plates is slightly higher than the price of coils.

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*Top 20 companies in steel industry trade volume.

*Customized processing steel one-stop purchase.

*Exports of steel exceeded tens of billions for 5 consecutive years.

**We have a complete set of testing equipment, such as ut & ET, hydraulic testing equipment, spectrometer, scanning electron microscope, etc, and have passed SGS TUV

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