No. 20 steel is a high-quality carbon structural steel, its chemical composition and mechanical properties are as follows:

Chemical composition (mass fraction, %) : 

C：0.17~0.23，(Si)：0.17~0.37，(Mn)：0.35~0.65，(P)：≤0.035，(S)：≤0.035，(Cr)：≤0.25，(Ni)：≤0.30，(Cu)：≤0.25

Mechanical property

Tensile strength: ≥410MPa

Yield strength: ≥245MPa

Elongation after breaking: ≥25%

Section shrinkage: ≥55%

Hardness: No heat treatment, ≤156HB

The chemical composition of No. 20 steel determines its basic characteristics, while the mechanical properties reflect the bearing capacity and deformation of this steel in practical applications. These performance indicators provide designers and engineers with the basic data for the selection and use of No. 20 steel.

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No.10 tempering chemical ingredients: C: 0.07~0.13, Si: 0.17 ~ 0.37, Mn: 0.35 ~ 0.65, S: ≤0.035, P: ≤0.035, Cr: ≤0.15, Ni: ≤0.25, Cu: ≤0.25

No. 10 steel mechanical properties:

Tensile strength σb(MPa) : ≥335

Yield strength σs(MPa) : ≥205

Elongation δ5(%) : ≥31

Section shrinkage (%) : ≥55,

Hardness: No heat treatment,≤137HBs,

Sample size: 25mm longitudinal.

The steel has good cold plasticity, excellent performance after normalizing or high temperature tempering of the plate, good chip performance of the cold drawing normalizing state than the annealed state, excellent weldability, no tempering brittleness, strength slightly higher than 08/08F steel, plasticity, toughness is very good, easy to cold and hot processing molding, but hardenability and hardenability are poor.