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GB/T 1591 Q355MB vs CSA G40.21 300W

Minimal Match — 35% match based on chemical composition and mechanical property overlap.

GB/T 1591 Q355MB (GB/T 1591:2018) and CSA G40.21 300W (CSA G40.21-13 (R2023)) are both steel grades. Both fall under the Structural Steel category. GB/T 1591 Q355MB is typically used for general structure for engineering (plates, strips, bars and sections), while CSA G40.21 300W is commonly used for structural fabrication,bridges,buildings,machinery frames,general construction,welded structures. GB/T 1591 Q355MB is defined under Guobiao Standards (GB/T), originating from China, while CSA G40.21 300W is defined under Canadian Standards Association (CSA), originating from Canada.

As per chemical composition, GB/T 1591 Q355MB vs CSA G40.21 300W is a 58.2% match. As per mechanical properties, the match is 27.8%. Combined, this makes them a minimal match overall at 35%.

Frequently Compared With GB/T 1591 Q355MB:
CSA G40.21 400W CSA G40.21 480W CSA G40.21 260W CSA G40.21 350W CSA G40.21 400A ASTM A1008 SS Grade 50 ASTM A1008 SS Grade 80 ASTM A572 Gr.65
Other Structural Steel Grades to Compare With GB/T 1591 Q355MB:
GOST 19281 09G2S AS/NZS 3679.1 300 AS/NZS 3679.1 350 ASTM A283C
Match Breakdown
CHEMISTRY MATCH
58.2%
MECHANICAL MATCH
27.8%
OVERALL
35%
Specifications
Property GB/T 1591 Q355MB CSA G40.21 300W
Standard GB/T 1591:2018 CSA G40.21-13 (R2023)
Category Structural Steel Structural Steel
C (%) <=0.14 <=0.23
Si (%) <=0.50 Not specified
Mn (%) <=1.60 <=1.50
P (%) <=0.035 <=0.040
S (%) <=0.035 <=0.050
Nb (%) 0.01-0.05 Not specified
V (%) 0.01-0.10 Not specified
Ti (%) 0.006-0.05 Not specified
Cr (%) <=0.30 Not specified
Ni (%) <=0.50 Not specified
Cu (%) <=0.40 Not specified
Mo (%) <=0.10 Not specified
N (%) <=0.015 Not specified
Al (%) >=0.015 Not specified
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 Q355MB CSA G40.21 300W
Tensile Strength 470-630 MPa 450-620 MPa
Yield Strength >=355 MPa 300 MPa min
Elongation >=22% 20-23 %
Condition Thermomechanical processed (TMCP), nominal thickness or diameter up to 16 mm (tensile strength: up to 40 mm) Not specified
Typical Applications
GB/T 1591 Q355MB
General structure for engineering (plates, strips, bars and sections)
CSA G40.21 300W
structural fabrication,bridges,buildings,machinery frames,general construction,welded structures
Key Differences
Can GB/T 1591 Q355MB Be Substituted With CSA G40.21 300W?
GB/T 1591 Q355MB and CSA G40.21 300W 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 Q355MB
No active listings currently.
CSA G40.21 300W
Plate → (2 listings)
Thickness: 10–10 mm (0.39–0.39 in)
Width: 1500–1500 mm (59.06–59.06 in)
Length: 2700–2800 mm (106.3–110.24 in)
On M-EX Right Now
GB/T 1591 Q355MB
0 active listings and RFQs →
CSA G40.21 300W
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between GB/T 1591 Q355MB and CSA G40.21 300W?
GB/T 1591 Q355MB specifies Si, Nb, V, Ti which are not specified for CSA G40.21 300W.
Can GB/T 1591 Q355MB be substituted with CSA G40.21 300W?
GB/T 1591 Q355MB and CSA G40.21 300W 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.