Close Alternative — 75.5% match
based on chemical composition and mechanical property overlap.
GB/T 699 45 (GB/T 699:2015) and GB/T 699 40Mn (GB/T 699:2015) are both steel grades.
Both fall under the Carbon Steel category.
GB/T 699 45 is typically used for used for shafts, gears, bolts, connecting rods, axles, and hydraulic components., while GB/T 699 40Mn is commonly used for hot-rolled or forged quality carbon structural steel bars up to 250 mm.
GB/T 699 45 is defined under Guobiao Standards (GB/T), originating from China, while GB/T 699 40Mn is defined under Guobiao Standards (GB/T), originating from China.
As per chemical composition, GB/T 699 45 vs GB/T 699 40Mn is a 88.2% match.
As per mechanical properties, the match is 50%.
Combined, this makes them a close alternative overall at 75.5%.
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 699 45
GB/T 699 40Mn
Tensile Strength
>=600 MPa
>=590 MPa
Yield Strength
>=355 MPa
>=355 MPa
Elongation
>=16%
>=17%
Hardness
<=229 HB (as delivered, not heat treated)
<=229 HB (as delivered, not heat treated)
Condition
Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state
Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state
Typical Applications
GB/T 699 45
Used for shafts, gears, bolts, connecting rods, axles, and hydraulic components.
GB/T 699 40Mn
Hot-rolled or forged quality carbon structural steel bars up to 250 mm
Can GB/T 699 45 Be Substituted With GB/T 699 40Mn?
GB/T 699 45 and GB/T 699 40Mn 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 GB/T 699 45 and GB/T 699 40Mn?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can GB/T 699 45 be substituted with GB/T 699 40Mn?
GB/T 699 45 and GB/T 699 40Mn 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.