Q345B I-Beam, S355JR / A572 Gr.50 I Beam GB/T706 EN10025 ASTM A6

High yield strength, excellent load-bearing capacity
Good impact toughness for medium & heavy load projects
Fine weldability and easy cutting & processing
Stable mechanical performance, uniform microstructure
Wide size range, cost-effective low alloy structural steel

Product Overview

Q345B hot rolled I-Beam is a widely used low alloy high strength structural steel, equivalent grade S355JR and A572 Gr.50, manufactured following GB/T706, EN10025 and ASTM A6 standards.

The cross-section of I-beam features strong bending resistance, which makes it ideal for structural load bearing. Q345B I-beam delivers balanced mechanical properties, reliable plasticity and great weldability. It can be processed via cutting, drilling and welding.

This grade I beam is commonly used in workshop frames, mechanical equipment supports, bridge auxiliary structures, transportation infrastructure and general heavy engineering. We supply full size range hot rolled I-Beam, surface can be black, pickled or shot blasted as requested. Custom length cutting service available.

I-Beam

Chemical & Mechanical Property Snapshot

Grade	C(Max,%)	Si(%)	Mn(%)	P(Max,%)	S(Max,%)	Min Yield Strength(MPa)	Tensile Strength(MPa)	Elongation Min(%)	Impact Test
Q345B	0.20	≤0.50	1.00~1.60	0.035	0.035	345	470~630	21	+20℃ Charpy V-notch

Detailed Technical Specifications

Item	Specification
Product Name	Q345B Hot Rolled I-Beam
Equivalent Grade	S355JR, A572 Gr.50
Standards	GB/T706, EN10025, ASTM A6
Surface	Black / Shot blasting / Pickling
Size Range	10# ~ 63# I-beam, custom sizes available
Length	6m,9m,12m or custom cut length
MOQ	5 Ton
Delivery Time	7-15 working days
Package	Bundled with steel strips, export seaworthy packing
Tolerance	Meet GB/T706 / EN10025 dimensional tolerance

Dimension Table

Designation	Height (H) mm	Flange Width (B) mm	Web Thickness (tw) mm	Flange Thickness (tf) mm	Weight kg/m	Section Area cm²
I10#	100	68	4.5	7.6	11.26	14.3
I12#	120	74	5.0	8.4	13.99	17.8
I14#	140	80	5.5	9.1	16.89	21.5
I16#	160	88	6.0	9.9	20.51	26.1
I18#	180	94	6.5	10.7	24.14	30.8
I20a	200	100	7.0	11.4	27.91	35.5
I20b	200	102	9.0	11.4	31.07	39.5
I22a	220	110	7.5	12.3	33.07	42.0
I22b	220	112	9.5	12.3	36.52	46.4
I25a	250	116	8.0	13.0	38.11	48.5
I25b	250	118	10.0	13.0	42.03	53.5
I28a	280	122	8.5	13.7	43.49	55.4
I28b	280	124	10.5	13.7	47.89	61.0
I30a	300	126	9.0	14.4	48.00	61.2
I30b	300	128	11.0	14.4	52.79	67.2
I30c	300	130	13.0	14.4	57.50	73.2
I36a	360	136	10.0	15.8	60.04	76.3
I36b	360	138	12.0	15.8	65.69	83.5
I36c	360	140	14.0	15.8	71.34	90.7
I40a	400	142	10.5	16.5	67.59	86.1
I40b	400	144	12.5	16.5	73.87	94.1
I40c	400	146	14.5	16.5	80.16	102.1
I45a	450	150	11.5	18.0	80.42	102.4
I45b	450	152	13.5	18.0	87.48	111.4
I45c	450	154	15.5	18.0	94.55	120.4
I56a	560	166	12.5	21.0	106.32	135.4
I56b	560	168	14.5	21.0	115.11	146.5
I56c	560	170	16.5	21.0	123.90	157.6
I63a	630	176	13.0	22.0	121.41	154.7
I63b	630	178	15.0	22.0	131.30	167.3
I63c	630	180	17.0	22.0	141.19	179.9
IPN80	80	42	3.9	5.9	6.0	7.6
IPN100	100	50	4.5	6.8	8.3	10.6
IPN120	120	58	5.1	7.7	11.1	14.2
IPN140	140	66	5.7	8.6	14.3	18.3
IPN160	160	74	6.3	9.5	17.9	22.8
IPN180	180	82	6.9	10.4	21.9	27.9
IPN200	200	90	7.5	11.3	26.2	33.4
IPN220	220	98	8.1	12.2	31.1	39.5
IPN240	240	106	8.7	13.1	36.4	46.2
IPN270	270	114	9.5	14.2	42.2	53.7
IPN300	300	124	10.2	15.3	48.1	61.3
IPN330	330	133	11.0	16.3	54.7	69.7
IPN360	360	142	11.8	17.4	61.2	78.2
IPN400	400	152	12.8	18.6	69.4	88.5
IPN450	450	165	14.0	20.0	79.6	101.5
IPN500	500	177	15.2	21.3	90.7	115.7
IPN550	550	190	16.5	22.7	103.0	131.2
S6×12.5	152.4	63.5	4.3	7.5	18.6	23.7
S8×18.4	203.2	80.0	5.3	8.8	27.4	34.9
S10×25.4	254.0	88.9	6.1	10.2	37.8	48.1
S12×31.8	304.8	101.6	6.6	10.9	47.3	60.1
S15×42.9	381.0	127.0	7.9	12.8	63.8	81.1
S18×54.7	457.2	152.4	9.0	14.5	81.4	103.5
S20×65.4	508.0	152.4	10.0	16.0	97.3	123.7
S24×79.9	609.6	177.8	10.9	17.4	119.0	151.3
IS100	100	50	4.2	7.2	8.4	10.7
IS125	125	65	4.8	8.1	11.9	15.1
IS150	150	75	5.4	9.0	15.7	19.9
IS200	200	100	6.2	10.2	25.4	32.3
IS250	250	125	6.9	11.6	37.3	47.5
IS300	300	150	7.6	13.0	50.7	64.5
IS350	350	165	8.1	14.2	61.8	78.6
IS400	400	180	8.6	15.3	72.5	92.2

Product Comparison Table

Material Grade	Equivalent International Grade	Standard	Min Yield Strength (MPa)	Tensile Strength (MPa)	Core Features	Typical Application
Q345B	S355JR / A572 Gr.50	GB/T706, EN10025, ASTM A6	345	470~630	Classic low alloy steel, stable performance, good weldability	Mechanical bases, equipment supports, workshop frames

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FAQs

What is the equivalent grade of Q345B I-Beam?

Q345B I-Beam is equivalent to S355JR (EU standard) and A572 Gr.50 (ASTM standard).

What temperature impact test for Q345B?

Q345B requires Charpy V-notch impact test at +20℃, it is not designed for low-temperature severe cold environment.

What standard does your Q345B I-beam follow?

Our Q345B hot rolled I-beam complies with GB/T706, EN10025 and ASTM A6. Mill test certificate (MTC) can be provided.

Can I get custom cut length Q345B I-Beam?

Yes, we provide cutting service, we can cut I-beam to your required project length.

What is the main application of Q345B I beam?

It is widely used for mechanical equipment support, factory building frames, platform structures and heavy load civil engineering.

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Q345B I-Beam, S355JR / A572 Gr.50 I Beam GB/T706 EN10025 ASTM A6