AISI 4140 Steel Equivalent – Global Standards and Comparison
In today’s globalized supply chain, engineers and buyers often face one challenge: understanding how steel grades from different standards relate to each other. AISI 4140 steel equivalent designations are critical when sourcing materials across borders. Whether you’re working in Europe, Asia, or the United States, you’ll encounter different codes like 42CrMo4, SCM440, or EN19 that match AISI 4140. This article explains the equivalence, compares properties, and provides insights for procurement.
🌍 Why Knowing AISI 4140 Steel Equivalents Matters
Steel standards differ depending on the region. While American companies use the AISI 4140 steel international standards (ASTM/SAE), European buyers prefer DIN or EN grades, and Asian suppliers often list JIS or GB numbers. Understanding equivalents ensures you select the right material without confusion or costly mistakes.
🔬 AISI 4140 Steel Composition and Properties
Before looking at aisi 4140 equivalent grades, let’s recap its chemical composition:
| Element | Content (%) |
|---|---|
| Carbon | 0.38 – 0.43 |
| Chromium | 0.80 – 1.10 |
| Molybdenum | 0.15 – 0.25 |
| Manganese | 0.75 – 1.00 |
| Silicon | 0.15 – 0.30 |
| Phosphorus | ≤ 0.035 |
| Sulfur | ≤ 0.040 |
These elements provide excellent strength, toughness, and hardenability. In mechanical terms, aisi 4140 steel properties comparison shows:
| Property | Typical Value |
|---|---|
| Tensile Strength | 850–1000 MPa (123–145 ksi) |
| Yield Strength | 650–850 MPa (94–123 ksi) |
| Hardness (Q&T) | 28–32 HRC |
| Elongation | 12–18 % |
📊 AISI 4140 Equivalent Grades
Here’s a quick aisi 4140 equivalent material reference across global standards:
| Standard | Equivalent Grade | Notes |
|---|---|---|
| DIN (Germany) | 42CrMo4 | Widely used in Europe, nearly identical chemistry. |
| JIS (Japan) | SCM440 | Popular in Japan/Korea, often used for automotive parts. |
| BS (UK) | EN19 | British equivalent, known for toughness in shafts/gears. |
| GB (China) | 42CrMo | Common in China, shares mechanical properties. |
| ASTM/SAE (USA) | AISI 4140 | American designation under SAE-AISI. |
⚖️ AISI 4140 vs 42CrMo4
When comparing aisi 4140 vs 42CrMo4, the differences are negligible. Both have 0.40% carbon, ~1% chromium, and ~0.20% molybdenum. Mechanical behavior is nearly identical. European buyers often specify 42CrMo4, while American engineers use 4140.
⚖️ AISI 4140 Steel vs SCM440
aisi 4140 steel vs scm440 comes up frequently in Asian markets. SCM440 is the JIS equivalent grade, with slight variations in phosphorus/sulfur limits. Performance remains the same: both provide high fatigue resistance and toughness for gears, axles, and high-strength fasteners.
⚖️ AISI 4140 vs EN19
Another common comparison is aisi 4140 vs en19. EN19 is the British standard, popular for automotive shafts and industrial gear systems. Chemically, EN19 matches 4140 closely, and users can substitute one for the other in most applications.
🔥 Importance of Equivalent Materials in Procurement
Understanding aisi 4140 equivalent grades helps buyers:
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Source Globally – Choose reliable suppliers without confusion over local designations.
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Ensure Consistency – Match mechanical performance across international projects.
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Streamline Logistics – Replace hard-to-find grades with equivalents when needed.
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Cut Costs – Broader options often mean more competitive pricing.
🛠️ Common Applications
Engineers choose aisi 4140 steel applications (and its equivalents) for:
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Automotive: Crankshafts, gears, connecting rods.
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Oil & Gas: Drill collars, wellhead components.
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Aerospace: Landing gear and heavy-duty bolts.
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Machinery: Shafts, spindles, high-strength fasteners.
These parts demand consistent performance—knowing equivalents ensures reliability no matter where you source steel.
📈 Example: Mechanical Properties in Different Standards
Here’s a aisi 4140 steel properties comparison between international equivalents:
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Hardness (HRC) |
|---|---|---|---|
| AISI 4140 | 850–1000 | 650–850 | 28–32 |
| 42CrMo4 | 850–1000 | 650–850 | 28–32 |
| SCM440 | 850–980 | 620–850 | 28–32 |
| EN19 | 850–1000 | 650–850 | 28–32 |
| 42CrMo | 850–1000 | 650–850 | 28–32 |
This chart confirms the close match among global equivalents.
🌍 Company Advantages – Why Choose Otai Special Steel?
At Otai Special Steel, we supply AISI 4140 steel equivalent grades including 42CrMo4, SCM440, and EN19.
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📦 Large Inventory – Over 10,000 tons of alloy steel in plate, round bar, and forged blocks.
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🔍 Quality Control – UT testing, chemical analysis, third-party inspections (SGS, TUV).
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🏭 Processing Services – Cutting, heat treatment, machining.
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🌐 Global Network – Experienced in international logistics and export compliance.
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💰 Cost-Effective – Competitive prices with consistent supply.
❓ FAQ
Q1: Is AISI 4140 the same as 42CrMo4?
A: Yes, they are considered equivalent, with nearly identical composition and performance.
Q2: What is the difference between AISI 4140 and SCM440?
A: Very minor chemical variations, but mechanical properties remain the same.
Q3: Can I substitute EN19 for AISI 4140?
A: Yes, EN19 is the British equivalent grade and interchangeable in most cases.
Q4: Why are equivalents important in steel procurement?
A: They ensure consistent performance across international projects and simplify sourcing.
Q5: Do all equivalents have the same hardness range?
A: Yes, typically 28–32 HRC after quenching and tempering.
