ASTM A387/A387M Grade 21 vs ASTM A387/A387M Grade 5
Close Alternative — 84.9% match
based on chemical composition and mechanical property overlap.
ASTM A387/A387M Grade 21 (ASTM A387/A387M:2011) and ASTM A387/A387M Grade 5 (ASTM A387/A387M:2011) are both steel grades.
Both fall under the Alloy Steel category.
ASTM A387/A387M Grade 21 is typically used for welded boilers and pressure vessels for elevated temperature service, while ASTM A387/A387M Grade 5 is commonly used for welded boilers and pressure vessels for elevated temperature service.
ASTM A387/A387M Grade 21 is defined under ASTM International, originating from United States, while ASTM A387/A387M Grade 5 is defined under ASTM International, originating from United States.
As per chemical composition, ASTM A387/A387M Grade 21 vs ASTM A387/A387M Grade 5 is a 80% match.
As per mechanical properties, the match is 100%.
Combined, this makes them a close alternative overall at 84.9%.
Frequently Compared With ASTM A387/A387M Grade 21:
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
ASTM A387/A387M Grade 21
ASTM A387/A387M Grade 5
Tensile Strength
415-585 MPa
415-585 MPa
Yield Strength
>=205 MPa
>=205 MPa
Elongation
>=18%
>=18%
Condition
Class 1 plates, no thickness ranges printed; elongation in 50 mm gauge length
Class 1 plates, no thickness ranges printed; elongation in 50 mm gauge length
Typical Applications
ASTM A387/A387M Grade 21
Welded boilers and pressure vessels for elevated temperature service
ASTM A387/A387M Grade 5
Welded boilers and pressure vessels for elevated temperature service
Can ASTM A387/A387M Grade 21 Be Substituted With ASTM A387/A387M Grade 5?
ASTM A387/A387M Grade 21 and ASTM A387/A387M Grade 5 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.
What is the difference between ASTM A387/A387M Grade 21 and ASTM A387/A387M Grade 5?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can ASTM A387/A387M Grade 21 be substituted with ASTM A387/A387M Grade 5?
ASTM A387/A387M Grade 21 and ASTM A387/A387M Grade 5 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.