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E: enquiry@qilumetal.com
E: enquiry@qilumetal.com
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42CrMo4 / 1.7225 is the most commonly used alloy steel belongs to European standard EN10083-3 and EN10250-3. It could be used in many different industries, such as petrochemical engineering, machining and manufacturing, aerospace and automobile industry etc, so you could find its equivalent steel from different country standard, such as ASTM 4140 from American standard ASTM A29/A29M, SCM440 from Japanese standard JIS G4105, 42CrMo from Chinese standard GB/T1299, 708M40/EN19 from British standard BS970.
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AISI 4140 (equivalent to DIN 42CrMo4 1.7225, JIS SCM440, and BS 708M40) is a high-performance quenching and tempering alloy steel widely recognized for its exceptional mechanical properties. As a key member of the Cr-Mo steel family, it features a carbon content of 0.38-0.45%, which, when combined with chromium (0.8-1.2%) and molybdenum (0.15-0.30%) additions, delivers a balanced blend of strength, toughness, and wear resistance.
This alloy steel undergoes strict quenching and tempering (QT) processes, making it suitable for demanding applications across industries like automotive, aerospace, and heavy machinery. Its versatility is further enhanced by its compatibility with various manufacturing processes, including forging, machining, and heat treatment, ensuring consistent performance in both small components and large structural parts.
The carefully calibrated chemical makeup of AISI 4140 and its equivalents ensures optimal performance. Key elements include:
Grade | C | Si | Mn | Cr | Mo |
AISI 4140 | 0.38-0.43 | 0.15-0.35 | 0.75-1.00 | 0.8-1.1 | 0.15-0.25 |
DIN 42CrMo4 1.7225 | 0.38-0.45 | 0.4Max | 0.6-0.9 | 0.9-1.2 | 0.15-0.30 |
JIS SCM440 | 0.38-0.43 | 0.15-0.35 | 0.6-0.85 | 0.9-1.2 | 0.15-0.30 |
This composition minimizes impurities (phosphorus ≤ 0.035%, sulfur ≤ 0.04%), reducing brittleness and improving structural integrity.
After QT treatment, AISI 4140 exhibits impressive mechanical performance, varying slightly with size:
Size Range | Tensile Strength | Yield Strength | Elongation |
d≤16mm / t≤8mm | 1100-1300 Mpa | 900 Mpa Min | 10% Min |
16＜d≤40mm / 8＜t≤20mm | 1100-1200 Mpa | 750 Mpa Min | 11% Min |
40＜d≤100mm / 20＜t≤60mm | 900-1100 Mpa | 650 Mpa Min | 12% Min |
These properties make it ideal for load-bearing components requiring both strength and ductility.
AISI 4140 responds well to various heat treatments, allowing customization for specific needs:
· Quenched and Tempered (+QT): Achieves a hardness range of HRC28-32 (common for general applications).
· Flame/Induction Hardening: Reaches 53 HRC for high-wear surfaces.
· Soft Annealed (+A): Reduces hardness to HB241 Max for easier machining.
It is available in multiple forms to suit manufacturing needs:
· Cold drawn bars: Φ3-Φ80mm, length 6000-9000mm
· Hot rolled bars: Φ16-Φ310mm, length 6000-9000mm
· Hot forged bars: Φ100-Φ1200mm, length 3000-5800mm
AISI 4140 is a staple in automotive manufacturing, used for:
· Crankshafts and connecting rods (withstanding high rotational stress).
· Transmission gears (resisting wear from constant meshing).
Its high strength-to-weight ratio makes it suitable for:
· Aircraft engine components and landing gear parts (supporting heavy loads during takeoff/landing).
· Missile and drone structural elements (withstanding extreme pressure).
Common applications include:
· Machine tool spindles and shafts (maintaining precision under high torque).
· Mining crusher gears and conveyor couplings (resisting abrasion from debris).
While both are Cr-Mo alloy steels, DIN 42CrMo4 1.7225 has a slightly wider carbon range (0.38-0.45% vs. 0.38-0.43% for AISI 4140) and higher molybdenum content (0.15-0.30% vs. 0.15-0.25%), leading to marginally better hardenability.
Weldability is limited due to its carbon content (≈0.42%). Pre-heating (to 200-300°C) and post-weld tempering are recommended to reduce cracking risks.
We maintain large stocks of hot rolled bars (Φ16-Φ310mm) and forged bars (Φ310-Φ550mm). For specific sizes, contact our sales team for real-time updates.
AISI 4140 (equivalent to DIN 42CrMo4 1.7225, JIS SCM440, and BS 708M40) is a high-performance quenching and tempering alloy steel widely recognized for its exceptional mechanical properties. As a key member of the Cr-Mo steel family, it features a carbon content of 0.38-0.45%, which, when combined with chromium (0.8-1.2%) and molybdenum (0.15-0.30%) additions, delivers a balanced blend of strength, toughness, and wear resistance.
This alloy steel undergoes strict quenching and tempering (QT) processes, making it suitable for demanding applications across industries like automotive, aerospace, and heavy machinery. Its versatility is further enhanced by its compatibility with various manufacturing processes, including forging, machining, and heat treatment, ensuring consistent performance in both small components and large structural parts.
The carefully calibrated chemical makeup of AISI 4140 and its equivalents ensures optimal performance. Key elements include:
Grade | C | Si | Mn | Cr | Mo |
AISI 4140 | 0.38-0.43 | 0.15-0.35 | 0.75-1.00 | 0.8-1.1 | 0.15-0.25 |
DIN 42CrMo4 1.7225 | 0.38-0.45 | 0.4Max | 0.6-0.9 | 0.9-1.2 | 0.15-0.30 |
JIS SCM440 | 0.38-0.43 | 0.15-0.35 | 0.6-0.85 | 0.9-1.2 | 0.15-0.30 |
This composition minimizes impurities (phosphorus ≤ 0.035%, sulfur ≤ 0.04%), reducing brittleness and improving structural integrity.
After QT treatment, AISI 4140 exhibits impressive mechanical performance, varying slightly with size:
Size Range | Tensile Strength | Yield Strength | Elongation |
d≤16mm / t≤8mm | 1100-1300 Mpa | 900 Mpa Min | 10% Min |
16＜d≤40mm / 8＜t≤20mm | 1100-1200 Mpa | 750 Mpa Min | 11% Min |
40＜d≤100mm / 20＜t≤60mm | 900-1100 Mpa | 650 Mpa Min | 12% Min |
These properties make it ideal for load-bearing components requiring both strength and ductility.
AISI 4140 responds well to various heat treatments, allowing customization for specific needs:
· Quenched and Tempered (+QT): Achieves a hardness range of HRC28-32 (common for general applications).
· Flame/Induction Hardening: Reaches 53 HRC for high-wear surfaces.
· Soft Annealed (+A): Reduces hardness to HB241 Max for easier machining.
It is available in multiple forms to suit manufacturing needs:
· Cold drawn bars: Φ3-Φ80mm, length 6000-9000mm
· Hot rolled bars: Φ16-Φ310mm, length 6000-9000mm
· Hot forged bars: Φ100-Φ1200mm, length 3000-5800mm
AISI 4140 is a staple in automotive manufacturing, used for:
· Crankshafts and connecting rods (withstanding high rotational stress).
· Transmission gears (resisting wear from constant meshing).
Its high strength-to-weight ratio makes it suitable for:
· Aircraft engine components and landing gear parts (supporting heavy loads during takeoff/landing).
· Missile and drone structural elements (withstanding extreme pressure).
Common applications include:
· Machine tool spindles and shafts (maintaining precision under high torque).
· Mining crusher gears and conveyor couplings (resisting abrasion from debris).
While both are Cr-Mo alloy steels, DIN 42CrMo4 1.7225 has a slightly wider carbon range (0.38-0.45% vs. 0.38-0.43% for AISI 4140) and higher molybdenum content (0.15-0.30% vs. 0.15-0.25%), leading to marginally better hardenability.
Weldability is limited due to its carbon content (≈0.42%). Pre-heating (to 200-300°C) and post-weld tempering are recommended to reduce cracking risks.
We maintain large stocks of hot rolled bars (Φ16-Φ310mm) and forged bars (Φ310-Φ550mm). For specific sizes, contact our sales team for real-time updates.
