SCM440 ALLOY STEEL-JIS G4105

SCM440 alloy steel manufacturers and suppliers,supplied with round rods,square/flat bars,rollers,shafts,blocks and forging pieces.

SCM440 grade is a low-alloy steel including chromium and molybdenum as strengthening elements which has good strength and toughness, ductility,weldability and machinability. SCM440  is widely used in the automotive, agricultural ,oil and gas industry. Typical uses are forged gears and shafts, spindles, fixtures, jigs and collars.

SCM440 ALLOY STEEL-JIS G4105

1.Chemical Composition

C Mn Si Cr Mo P S
Min 0.38 0.6 0.15 0.9 0.15
Max 0.43 0.85 0.35 1.2 0.3 0.03 0.03

2.Related Specifications

ASTM/AISI:4140/4142
EN/DIN:42CrMo4/Din 1.7225
BS:EN19/708M40
GB:42CrMo

3.Heat Treatment For SCM440 steel

  • Normalizing:850℃-900℃,Cool in air
  • Annealing:830-850℃,Cool in furnace
  • Hardening:830 – 880°C,oil quench is recommended
  • Tempering:530°C – 630°C, cool in still air

SCM440 Steel Quenching DiagramSCM440 Steel Quenching Diagram

SCM440 Steel Tempering DiagramSCM440 Steel Tempering Diagram

4.SCM440 Steel Mechanical Property with Quenched and Tempered condition as per JIS G4105


Tensile,Mpa Yield,Mpa Elongation,% Reduction,% Charpy Impact,J Hardness,HBW
≥980.7 ≥834 ≥12 ≥45 -≥59 285-352

5.Supply Size & Condition For SCM440

  • Round Bars:  Dia.80 – 1,000mm as Forged
  • Flat / Square Bars:  Thickness Max.800mm
  • Shafts, Rollers, Blocks:  Customized or According to Drawing
  • Rolled Round Bars:  Dia.16 – 350mm with UT Assurance

Heat treatment:Quenched and Tempered (+QT), Normalizing (+N), Annealing (+A)
Surface finish:Black / Rough turned / Peeled

6.Quality Certification
A material test report(Inspection Certificate EN 10204 3.1) will be provided, documenting the following:
1.Chemical analysis
2.Mechanical properties
3.Surface hardness
4.Non Metallic Inclusion
5.Heat Treatment Process
6.Grain size
7.Forging ratio
8.NDE test method/criteria