1. Q235B

1.1 Q235B the most common used structural steel，It is often made into plate, profiles, bars and pipes. It is used to make steel bars or to steel structures of factory buildings, high-voltage transmission towers, bridges, vehicles, boilers, containers, ships and other steel structures and equipment frame shells, it is also widely used for machining parts with less performance requirements. Q235B steel should be the largest amount of steel on the market.

1.2 Chemical composition and mechanical properties

Chemical composition

	C %	Si %	Mn %	S %	P %	Cr %	Ni %	Cu %
	0.17—0.22	≤0.35	≤1.4	≤0.035

 

Mechanical properties

tensile strength ReH(MPa)  T≤16	Yield strength Rm (MPa)	Elongation δ10 (%)  T≤ 40	Section shrinkage ψ (%)
235	370-500	26

1.3 Equivalent to major foreign countries' steel grades: Japan JIS G3101  SS400； American ASTM A36 Gr.36； Europe EN-10025 S235JR

1.4 Delivery status. Hot rolling, thermal control, normalizing

1.5 Operative norm（GB）：GB/T 700

 

2. Q345B， Q345C，Q345D

2.1 Q345B is also the most commonly used steel material, it has plates, profiles, bars and pipes. Commonly used for making steel structures of buildings and factories, and equipment frame and structures, In addition to welding structural parts, it is also used to make a variety of machining parts, such as connectors, shafts, pins and other machined parts.

2.2 Chemical composition and mechanical properties

Chemical composition

	C %	Si %	Mn %	S % ≤	P % ≤	NB ≤	V ≤	Ti ≤	Cr % ≤	Ni % ≤	Cu % ≤
A	≤0.20	≤0.50	≤1.70	0.035	0.035	0.07	0.15	0.20	0.30	0.50	0.30
B				0.035	0.035
C				0.030	0.030
D	≤0.18			0.025	0.030
E				0.020	0.025

A-     No impact performance test, only conventional tension and cold bending.

B-     Impact test at room temperature (20 C) and the impact energy is 27J.

C-     Impact test at 0º C, the impact energy is 27J.

D-     Impact test at 27º C, the impact energy is 27J.

 

Mechanical properties

tensile strength ReH(MPa)  t=16-40mm	Yield strength Rm (MPa)  t≤ 40	Elongation δ10 (%)   t≤ 40	Section shrinkage ψ (%)
335	470-630	≥ 20

 

2.3 Equivalent to major foreign countries' steel grades: Japan- JIS G3106 SS490； American -ASTM A572 Gr. 50(345); Europe - EN-10025 S355JR

2.4 Delivery status. Hot rolling, thermal control, normalizing

2.5 Operative norm（GB）：GB/T1591-2008

 

3. Q345R

3.1 Q345R is also a common structural steel, mainly plate. Q345R steel is a special plate for pressure vessel with yield strength of 345 MPa. It has good comprehensive mechanical and technological properties. It is the most widely used pressure vessel structural steel plate in China.

3.2 Chemical composition and mechanical properties

Chemical composition

	C %	Si %	Mn %	S %	P %	Cr %	Ni %	Cu %
	≤0.20	≤0.55	1.20-1.60	≤0.010	≤0.025	≤0.30	≤0.30

 

Mechanical properties

tensile strength ReH(MPa) T16-36	Yield strength Rm (MPa)	Elongation δ10 (%)	Section shrinkage ψ (%)
500-630	345	21

 

3.3 Equivalent to major foreign countries' steel grades: Europe -EN10028  P265GH;  American - ASME SA516 Gr.70；Japan -JIS G3013 SB480

3.4 Delivery status. Hot rolling, thermal control, normalizing

3.5 Operative norm（GB）：GB713-2014

 

4. 20# steel

4.1 20# steel belongs to high quality low carbon steel, cold extruded, carburized hardened steel. The steel has low strength, but has good toughness, plasticity and weldability. The tensile strength is 355~410MPa and the elongation is more than 24%.

Quenching does not work for 20# steel, heat treatment process is relatively simple, usually raw material direct machining or forging normalization, for unimportant structural parts, connectors or stamping parts, or used as carburized steel. It is also used to make ordinary seamless steel tubes in China.

4.2 Chemical composition and mechanical properties

Chemical composition

	C %	Si %	Mn %	S %	P %	Cr %	Ni %	Cu %
	0.17-0.23	0.17-0.37	0.35-0.65	≤0.035	≤0.035	≤0.25	≤0.3	≤0.25

 

Mechanical properties

tensile strength ReH(MPa)	Yield strength Rm (MPa)	Elongation δ10 (%)	Section shrinkage ψ (%)
410	245	25	55

 

4.3 Equivalent to major foreign countries' steel grades: Europe- DIN EN10083-2 C22;  American - ASTM 1020;  Japan- JIS S20C

4.4 Delivery status. Hot rolling, thermal control, normalizing

4.5 Operative norm（GB）：GB/T 699-2015

 

 

5. 35# steel

5.1 35# is a high quality carbon structural steel with good plasticity and proper strength, good workmanship and “so-so” weldability. It is mostly used in normalizing and tempering state.

No. 35 steel is widely used in the manufacture of forgings and hot-pressed parts, cold-drawn and upset steel, seamless steel pipes, mechanical parts, such as crankshafts, rotating shafts, pins, levers, connecting rods, beams, sleeves, wheels, washers, screws, nuts etc. machining parts in China.

 

5.2 Chemical composition and mechanical properties

Chemical composition

	C %	Si %	Mn %	S %	P %	Cr %	Ni %	Cu %
	0.27-0.34	0.170.37	0.50-0.80	≤0.035	≤0.035	≤0.25	≤0.30	≤0.25

 

Mechanical properties

tensile strength ReH(MPa)	Yield strength Rm (MPa)	Elongation δ10 (%)	Section shrinkage ψ (%)
530	315	20	45

 

5.3 Equivalent to major foreign countries' steel grades: Europe- DIN EN10083-2 C35;  American - ASTM 1035;  Japan- JIS S35C

5.4 Delivery status. Hot rolling or hot forging. Heat treatment delivery (annealing, normalizing, high temperature tempering) can be made according to specific contract.

5.5 Operative norm（GB）：GB/T 699-2015

 

6. 45# steel

6.1 No. 45 steel is medium carbon structural steel. It has good cold and hot working properties, good mechanical properties, low price and wide source, so it is widely used. Its biggest weakness is that its hardenability is low, and the workpiece with large section size and high requirement is not suitable for use.

45 steel after quenched and tempered has good comprehensive mechanical properties and are widely used in various important structural machining parts, especially those connecting rods, bolts, gears and shafts working under alternating loads. The surface hardness of 45# steel is low and its wear resistance is not good, the surface hardness of parts can be improved by quenching and tempering + surface hardening. It is the most commonly used material for common shaft, pin and high strength bolts etc. machining parts in China.

 

6.2 Chemical composition and mechanical properties

Chemical composition

	C %	Si %	Mn %	S %	P %	Cr %	Ni %	Cu %
	0.42-0.5	0.17-0.37	0.5-0.8	≤0.035	≤0.035	≤0.25	≤0.3	≤0.25

 

Mechanical properties

tensile strength ReH(MPa)	Yield strength Rm (MPa)	Elongation δ10 (%)	Section shrinkage ψ (%)
600	355	16	40

 

6.3 Equivalent to major foreign countries' steel grades: Europe- DIN EN10083-2 C45;  American-ASTM 1045。Japan - JIS S45C

6.4 Delivery status. Hot rolling or hot forging. Heat treatment delivery (annealing, normalizing, high temperature tempering) can be made according to specific contract.

6.5 Operative norm（GB）：GB/T 699-2015

 

Here are just a few of the most commonly used structural steels in China. If you need more detailed information about Chinese steels materials and the steel grades comparison form between Chinese steel and other major foreign countries, please download it on my website for free!, please download them for free on my website!