EN19 Steel Properties

EN19 Steel, also known as 4140, 1.7225, SCM440, or 42CrMo4, is a high-quality quenched and tempered alloy structural steel. It belongs to the category of medium carbon steels and offers excellent strength, toughness, and wear resistance. In this blog post, we will delve into the properties, composition, heat treatment, and applications of EN19 Steel.

What is EN19 Steel?

EN19 steel, also known as 708M40 in the BS 970 standard, is a high-quality alloy steel used for various mechanical and engineering applications. It contains approximately 1% chromium and molybdenum.

It is considered equivalent to 42CrMo4 steel in the EN standard and 4140 steel in the ASTM standard. EN19 steel is renowned for its exceptional combination of toughness, strength, and resistance to wear.

It is extensively employed in the production of machinery components, automotive parts, gears, shafts, axles, and other similar applications. The “EN” prefix indicates compliance with European standards, while the number “19” identifies the specific steel grade within the EN standards.

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EN19 Steel Material Specification

EN19 is a high-quality alloy steel that is commonly used in engineering applications. It is also known as 709M40 or 42CrMo4 (1.7225) steel, which are alternative designations for the same material.

EN19 Steel Material Specification are:

  • BS 970-1955: EN19
  • BS 970-3-1991: 708M40
  • BS EN 10250: 42CrMo4
  • DIN: 1.7225
  • ASTM A29: 4140
  • JIS G4105: SCM440
  • AS 1444: 4140
  • AFNOR: 42CD4

EN 19 steel chemical Compositions

EN19 Steel has the following chemical composition:

  • Carbon (C): 0.35-0.45%
  • Silicon (Si): 0.10-0.35%
  • Manganese (Mn): 0.50-0.80%
  • Phosphorus (P): ≤0.035%
  • Sulfur (S): ≤0.050%
  • Chromium (Cr): 0.90-1.50%
  • Molybdenum (Mo): 0.20-0.40%

EN19 steel Mechanical Properties

Here are the mechanical properties of EN 19 alloy steel, provided in both metric and imperial units:

  • Tensile strength: 655 MPa (MegaPascals) / 95,000 psi (Pound per Square Inch)
  • Yield strength: 415 MPa / 60,200 psi
  • Bulk modulus (typical for steel): 140 GPa / 20,300 ksi (KiloPound per Square Inch)
  • Shear modulus (typical for steel): 80 GPa / 11,600 ksi
  • Elastic modulus: 190-210 GPa / 27,557-30,458 ksi
  • Poisson’s ratio: 0.27-0.30
  • Elongation at break (in 50 mm): 25.70%
  • Hardness (Brinell scale): 197
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EN19 Heat Treatment

EN19 Steel undergoes various heat treatment processes to achieve desired properties. EN19 steel heat treatment steps include:

  • Forging: Temperature range of 1050-850°C
  • Annealing: Temperature range of 680-720°C
  • Normalizing: Temperature range of 840-880°C
  • Quenching: Temperature range of 820-860°C (oil or water)
  • Tempering: Temperature range of 540-680°C

EN alloy steel Applications

EN19 Steel finds extensive use in engineering and industrial applications where high strength and toughness are required. Some common applications include:

  • Machine tool industry: Gears, shafts, spindles, bolts, studs, etc.
  • Automotive industry: Gear components, crankshafts, connecting rods, etc.
  • General engineering: Axles, crankshafts, torsion bars, fasteners, etc.


EN19 Steel is a versatile quenched and tempered alloy structural steel that offers excellent strength, toughness, and wear resistance. Its composition, combined with appropriate heat treatment, results in desirable mechanical properties suitable for various demanding applications.