Strong Match — 99.5% match
based on chemical composition and mechanical property overlap.
GB/T 1591 Q420C (GB/T 1591:2018) and GB/T 1591 Q420B (GB/T 1591:2018) are both steel grades.
Both fall under the Structural Steel category.
GB/T 1591 Q420C is typically used for general structure for engineering (plates, strips, bars and sections), while GB/T 1591 Q420B is commonly used for general structure for engineering (plates, strips, bars and sections).
GB/T 1591 Q420C is defined under Guobiao Standards (GB/T), originating from China, while GB/T 1591 Q420B is defined under Guobiao Standards (GB/T), originating from China.
As per chemical composition, GB/T 1591 Q420C vs GB/T 1591 Q420B is a 99.2% match.
As per mechanical properties, the match is 100%.
Combined, this makes them a strong match overall at 99.5%.
Other Structural Steel Grades to Compare With GB/T 1591 Q420C:
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 Q420C
GB/T 1591 Q420B
Tensile Strength
520-680 MPa
520-680 MPa
Yield Strength
>=420 MPa
>=420 MPa
Elongation
>=20%
>=20%
Condition
Hot-rolled (as-rolled), nominal thickness or diameter up to 16 mm for yield; tensile strength for up to 100 mm; elongation longitudinal, up to 40 mm
Hot-rolled (as-rolled), nominal thickness or diameter up to 16 mm for yield; tensile strength for up to 100 mm; elongation longitudinal, up to 40 mm
Typical Applications
GB/T 1591 Q420C
General structure for engineering (plates, strips, bars and sections)
GB/T 1591 Q420B
General structure for engineering (plates, strips, bars and sections)
Can GB/T 1591 Q420C Be Substituted With GB/T 1591 Q420B?
GB/T 1591 Q420C and GB/T 1591 Q420B overlap closely enough on chemistry and mechanical properties that GB/T 1591 Q420B is often considered as a substitute for GB/T 1591 Q420C in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.
What is the difference between GB/T 1591 Q420C and GB/T 1591 Q420B?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can GB/T 1591 Q420C be substituted with GB/T 1591 Q420B?
GB/T 1591 Q420C and GB/T 1591 Q420B overlap closely enough on chemistry and mechanical properties that GB/T 1591 Q420B is often considered as a substitute for GB/T 1591 Q420C in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.