Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Si
Mn
P
S
Cr
Mo
Ni
0.60-0.75
<=1.00
<=1.00
<=0.040
<=0.030
16.00-18.00
<=0.75
<=0.60
Mechanical Properties
Tensile Strength
>=590 MPa
Yield Strength
>=245 MPa
Elongation
>=15%
Hardness
<=255 HB
Condition
Annealed plate and strip; proof strength applies only when specified by the purchaser
More data from JIS G4304:2021
From the standard
Mechanical properties, annealed3 values
0.2 percent proof strength, min
245 MPa
Tensile strength, min
590 MPa
Elongation, min
15 %
0.2 percent proof strength applies only when specified by the purchaser. 1 N/mm2 = 1 MPa.
Source: JIS G 4304:2021, Table 12
Hardness, annealed3 scales
Brinell hardness HBW, max
255
Rockwell HRC, max
25
Vickers hardness HV, max
269
Any one of the hardness scales applies; if not specified the manufacturer selects. HRBW is used in case of dispute.
Source: JIS G 4304:2021, Table 12
Hardness, quenched and tempered1 value
Rockwell HRC, min
40
Applies when quenched and tempered at the purchaser's specification.
Source: JIS G 4304:2021, Table 13
Heat treatment (example, informative)3 settings
Annealing
about 750 deg C rapid cooling, or 800 to 900 deg C slow cooling
Hardening
1010 to 1070 deg C, rapid cooling
Tempering
150 to 400 deg C, air cooling
Annex JA is informative; temperatures are examples.
Source: JIS G 4304:2021, Table JA.4
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