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GB/T 1591 Q345B vs CSA G40.21 400A

Related Material — 60.2% match based on chemical composition and mechanical property overlap.

GB/T 1591 Q345B (GB/T 1591-2018) and CSA G40.21 400A (CSA G40.21-13 (R2023)) are both steel grades. Both fall under the Structural Steel category. GB/T 1591 Q345B is typically used for bridges, construction equipment, cranes, heavy structures, pressure vessels, machinery, while CSA G40.21 400A is commonly used for atmospheric corrosion-resistant (weathering) structural steel; exposed bridge girders and structural members where high strength and weathering resistance are both needed. GB/T 1591 Q345B is defined under Guobiao Standards (GB/T), originating from China, while CSA G40.21 400A is defined under Canadian Standards Association (CSA), originating from Canada.

As per chemical composition, GB/T 1591 Q345B vs CSA G40.21 400A is a 81.1% match. As per mechanical properties, the match is 18.3%. Combined, this makes them a related material overall at 60.2%.

Frequently Compared With GB/T 1591 Q345B:
CSA G40.21 300W CSA G40.21 480W GOST 19281 09G2S CSA G40.21 400W CSA G40.21 260W AS/NZS 3679.1 300 CSA G40.21 350W ASTM A1008 SS Grade 50 AS/NZS 3679.1 350 ASTM A572 Grade 50 ASTM A1008 SS Grade 80 ASTM A283C
Match Breakdown
CHEMISTRY MATCH
81.1%
MECHANICAL MATCH
18.3%
OVERALL
60.2%
Specifications
Property GB/T 1591 Q345B CSA G40.21 400A
Standard GB/T 1591-2018 CSA G40.21-13 (R2023)
Category Structural Steel Structural Steel
C (%) <=0.20 <=0.23
Si (%) <=0.50 <=0.40
Mn (%) 1.00-1.60 <=1.60
S (%) <=0.035 <=0.035
P (%) <=0.035 <=0.035
V (%) <=0.20 Not specified
Nb (%) <=0.07 Not specified
Ti (%) <=0.20 Not specified
Cu (%) Not specified 0.20-0.40
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property GB/T 1591 Q345B CSA G40.21 400A
Tensile Strength 470-630 MPa 520-670 MPa
Yield Strength >=345 MPa 400 MPa min
Elongation >=21% 17% min
Impact Energy >=34 J Not specified
Impact Not specified 27J at 0°C
Typical Applications
GB/T 1591 Q345B
bridges, construction equipment, cranes, heavy structures, pressure vessels, machinery
CSA G40.21 400A
Atmospheric corrosion-resistant (weathering) structural steel; exposed bridge girders and structural members where high strength and weathering resistance are both needed
Key Differences
Can GB/T 1591 Q345B Be Substituted With CSA G40.21 400A?
GB/T 1591 Q345B and CSA G40.21 400A share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.
Forms & Sizes Available on M-EX
GB/T 1591 Q345B
Plate → (2 listings)
Thickness: 10–10 mm (0.39–0.39 in)
Width: 1500–1500 mm (59.06–59.06 in)
Length: 3800–4000 mm (149.61–157.48 in)
CSA G40.21 400A
Plate → (2 listings)
Thickness: 10–10 mm (0.39–0.39 in)
Width: 1500–1500 mm (59.06–59.06 in)
Length: 2800–4200 mm (110.24–165.35 in)
On M-EX Right Now
GB/T 1591 Q345B
2 active listings and RFQs →
CSA G40.21 400A
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between GB/T 1591 Q345B and CSA G40.21 400A?
GB/T 1591 Q345B specifies V, Nb, Ti which are not specified for CSA G40.21 400A. CSA G40.21 400A specifies Cu which is not specified for GB/T 1591 Q345B.
Can GB/T 1591 Q345B be substituted with CSA G40.21 400A?
GB/T 1591 Q345B and CSA G40.21 400A share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.