SCM440 Alloy Steel

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Heat Treatment
Cold Processing
Hot Working

Grade :SCM440

Classification: Structural steel Chromium molybdenum steel

Standards:JIS G 4053 : Low-alloyed steels for machine structural use

Our supply size :

Diameter : 80 to 600 mm ;

Length : 1000 to 9000 mm ;

Our advantage :

  1. High Quality, Reasonable Price
  2. Over 40 Years Experience
  3. ISO NQA Certificated Factory
  4. Worldwide shipping
  5. Emergency Orders and Fast Delivery

Comparison of Materials


Chemical Composition(JIS G4051)



SCM440 is medium carbon chromium molybdenum alloy steel, which is an alloy steel containing chromium and molybdenum. It has the advantages of stable composition, low harmful elements, high steel purity, small decarburization layer and few surface defects. It is easy to be spheroidized and has low cold cracking rate. It is usually hardened and tempered. The ultimate tensile strength is 850-1000 Mpa. This material achieves a very good balance between strength, toughness and wear resistance. The chromium content of the alloy provides good hardness permeability, and the molybdenum element imparts average hardness and high strength.

SCM440 reacts well in heat treatment and it is easy to process under heat treatment conditions. This material provides many desirable properties such as good strength and wear resistance, excellent toughness, good ductility and resistance to high-temperature stresses.

Product Features:

  1. High strength and toughness.
  2. Great property of quenching and can be deep hardened.
  3. Less tempering brittleness tendency.
  4. Great machining performance under high temperature and nice appearance after machining.
  5. Good performance in weld ability.
  6. Excellent performance in impact absorption, such as where the hammer may bounce back and has barely any damage caused upon impact.

Conditions of heat treatment

Annealing: 830℃ Furnace Cooling

Normalization: 830~880℃ Air Cooling

Hardening: 830~880℃ Oil Cooling

Tempering: 530~630℃ Rapid Cooling

Criterion for heat treating conditions revise:

Ac: 750~790℃

Ar: 740~690℃

Ms: 310℃

Mechanical properties

Tensile strength (kgf/mm²): ≧100

Yield strength (kgf/mm²): ≧85

Elongation (%): ≧12

Cross section reduction rate (%): ≧45

Impact value (J/cm2): ≧6

Hardness (Hb) : 285~352

Forming Option

1 Hot rolling process

2 Hot Forging: Electro-hydraulic; High-speed-hydraulic; Oil-hydraulic; Precision-forging

Heat-treatment Option

1 +A: Annealed (full/soft/spheroidizing)

2 +N: Normalized

3 +NT: Normalized and tempered

4 +QT: Quenched and tempered (water/oil)

Surface Option

1 Black Surface

2 Grounded: Bright but rough ; Not precision

3 Machining for plate: Bright and precision; Little turning scar

4 Peeled/Turned: Bright and precision; Little turning scar

5 Polished: Very Bright and precision size; Not turning scar

Other Services

1 Cutting: Small pieces

2 CNC Machine: Produce as your drawing

3 Package: Bare/Nylon/Canvas/Wooden

4 Payment:T/T, L/C, O/A(request credit)

5 Transport:FOB/CFR/CIF/DDU/DDP (train/ship/Air)

Mill test certificate

EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.