ASTM 42CrMo4 + QT Alloy Steel Round Bars

ASTM 42CrMo4 alloy steel round bar with heat-treatment services to improve steel microstructure and mechanical properties.



Application: machine construction, base plates, axes, gear shafts, gear wheels

Surface condition: black, polished, rough machined, turned, painted, oil or grease covered

Chemical composition: C: 0.38 ~0.45; Si: ≤0.40; Mn:0.60~0.90; S: ≤0.035; P: ≤0.035; Cr:0.90~1.20; Mo: 0.15~0.30

Stock sizes:  φ30, φ35, φ40, φ45, φ50, φ60, φ65, φ70, φ90, φ100, φ110, φ130, φ120, φ140 mm

Equivalent grades

Standard Grade
GB 42CrMo
AISI 4140, 4142
BS 708M40, 708A42, 709M40
NF 40CD4, 42CD4
DIN 41CrMo4, 42CrMo4, 1.7225
ISO 683, 1 3
SAE 4140H, 4140RH

Mechanical composition

Tensile strength: min 1080 MPa

Yield strength : min 930 MPa

Elongation rate: min 12%

Reduction rate: min 45%

Impact energy: akv min 63J

Hardness: 32HRC ~52 HRC

Melting point: 1416 ℃

Formula reference:

Round bar weight KG = 3.14 x length x radius² x 0.00000785

Round pipe weight KG= 3.14 x length x (OD²-ID²) x 0.00000785

Plate weight KG= length x width x thickness x 0.00000785

(All lengths are mm)


We provide heat-treatment, cold thread, lab services according to customer’s technical requirements. Please send properties requriements to [email protected]. We will give positive response within one working day.

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Post time: Jun-13-2019