France · AFNOR NF

56 Si 7

NF A35-571 — Iron and steel. Alloy structural steels for hot formed spring manufacture(AM1-1977)

Chemical composition

wt% · log scale
0.010.1110C0.52 – 0.6Mn0.6 – 0.9P0.025S0.025Si1.5 – 2
  • min – max range
  • typical value

Mechanical properties

value range by condition
Yield strength Rp0.21300.00Tensile strength Rm1450.00Impact energy Kv/Ku13.00Elongation A6.00bars, flats, steel bars, wire, quenched and temperedHardnessFlat barbars, HR, steel bars, wire, hardened

Chemical composition

ElementminmaxSimilarRemarks
C0.520.6
Mn0.60.9
P0.025
S0.025
Si1.52

Mechanical properties

Heat treatment / conditionYield strengthTensile strengthElongationReduction of areaImpact energyHardness
bars, flats, steel bars, wire, quenched and tempered1300.001450.006.0013.00
bars, HR, steel bars, wire, hardenedFlat bar 56.00

Physical properties

Elastic modulusMean thermal expansionThermal conductivitySpecific heatResistivityDensityPoisson's ratio
206.00

Typical physical values

DensityElastic modulusPoisson's ratioRemarks
7.85200.00–207.000.27–0.30Material properties for low-carbon low-alloy steel. These values are not taken from the standard; they are indicative and must not be used for design.

Heat treatment

Type1
Heat-treatment curveHardness-Tempering
Heat-treatment curveHardenability
Heat-treatment curveTTT
Heat-treatment curveCCT

Similar grades

GradeRegionSystem
1.5026ItalyUNI
1.5026SpainUNE
1.5026RomaniaSTAS
1.5026SwedenSS
1.5026SwitzerlandSNV
1.5026FinlandSFS
1.5026PolandPN
1.5026AustriaONORM
1.5026NorwayNS
1.5026BelgiumNBN
1.5026HungaryMSZ
1.5026Czech RepublicCSN
1.5026BulgariaBDS
56 Si 7BulgariaBDS
1.5026United KingdomB.S.
1.5026FranceAFNOR NF
56 Si 7ItalyUNI
56 Si 7SpainUNE
56 Si 7RomaniaSTAS
56 Si 7SwedenSS
56 Si 7SwitzerlandSNV
56 Si 7FinlandSFS
56 Si 7PolandPN
56 Si 7AustriaONORM
56 Si 7NorwayNS
56 Si 7BelgiumNBN
56 Si 7HungaryMSZ
56 Si 7GermanyDIN
56 Si 7Czech RepublicCSN
56 Si 7United KingdomB.S.
1.5026GermanyDIN