42CrMo4 Chemical Composition: Elements, EN 10083-3 & Comparison
📑 Table of Contents
- 🔎 1. What Is 42CrMo4?
- 🧪 2. 42CrMo4 Chemical Composition
- ⚙️ 3. What Does Each Element Do in 42CrMo4?
- 📊 4. 42CrMo4 Composition vs 4140 and SCM440
- 🔥 5. How Chemical Composition Affects 42CrMo4 Properties
- 📏 6. 42CrMo4 Steel Plate and Material Selection
- 🏭 7. 42CrMo4 Heat Treatment and Composition
- 📋 8. How to Check 42CrMo4 Chemical Composition on an MTC
- 💰 9. Buying 42CrMo4 from a Steel Supplier
- 🏢 Otai Special Steel Advantages
- ❓ FAQ About 42CrMo4 Chemical Composition
🔎 1. What Is 42CrMo4?
42CrMo4 is a chromium-molybdenum alloy steel commonly supplied for quenched-and-tempered engineering components. The grade belongs to the European steel system and carries the material number 1.7225.
For buyers researching 42CrMo4 chemical composition, the most important point is that the grade relies on carbon, chromium, and molybdenum to achieve a useful combination of strength, hardenability, toughness, and fatigue resistance.
EN 10083-3 specifies the chemical composition of 42CrMo4. Under the commonly referenced EN 10083-3:2006 specification, the principal elements include carbon at 0.38–0.45%, manganese at 0.60–0.90%, chromium at 0.90–1.20%, and molybdenum at 0.15–0.30%. Silicon, phosphorus, and sulfur also have specified limits.
Although 42CrMo4 often appears in equivalent-grade charts alongside AISI 4140 and JIS SCM440, buyers should not treat the three designations as identical specifications. Different standards can define different chemistry limits and mechanical requirements.
42CrMo4 material number
The material number for 42CrMo4 is 1.7225. You may therefore see the material listed as “42CrMo4,” “42CrMo4 1.7225,” or simply “1.7225” in international steel quotations and technical documents.
When requesting a quotation, include both the grade and material number where possible. This helps the supplier identify the requested material more precisely.
🧪 2. 42CrMo4 Chemical Composition
The following table presents the chemical composition limits commonly specified for 42CrMo4 under EN 10083-3. These values represent standard requirements, not the actual chemistry of every production heat.
| Element | Chemical Composition, wt.% | Requirement Type |
|---|---|---|
| Carbon (C) | 0.38–0.45 | Specified range |
| Silicon (Si) | ≤ 0.40 | Maximum limit |
| Manganese (Mn) | 0.60–0.90 | Specified range |
| Phosphorus (P) | ≤ 0.025 | Maximum limit |
| Sulfur (S) | ≤ 0.035 | Maximum limit |
| Chromium (Cr) | 0.90–1.20 | Specified range |
| Molybdenum (Mo) | 0.15–0.30 | Specified range |
These composition limits are reported for 42CrMo4 under EN 10083-3.
42CrMo4 chemical composition at a glance
The name itself gives a useful indication of the alloy design. “42” refers approximately to the nominal carbon level of 0.42%, while “CrMo” indicates chromium and molybdenum as the key alloying elements.
The actual standard range is broader than the nominal value represented by the designation. For example, carbon does not remain fixed at exactly 0.42%; EN 10083-3 specifies a range of 0.38–0.45%.
This distinction becomes important when buyers compare a mill certificate with a material datasheet.
Standard composition is not the same as MTC chemistry
A steel standard defines an acceptable chemical range or limit. A steel mill then produces a particular heat within those requirements. The MTC records the measured chemistry of that actual heat.
Therefore, an MTC might show carbon below or above the nominal 0.42% value while still meeting the applicable standard. Buyers should compare the measured value with the standard limit rather than expect every MTC to show identical numbers.
⚙️ 3. What Does Each Element Do in 42CrMo4?
Understanding the role of each element helps buyers connect 42CrMo4 chemical composition with actual steel performance.
Carbon (C)
Carbon provides the basic hardening potential of the steel. The 0.38–0.45% carbon range allows 42CrMo4 to develop substantial hardness and strength after suitable quenching and tempering.
At the same time, higher carbon content generally makes welding more demanding. Therefore, fabrication engineers should consider the complete composition rather than looking at carbon alone.
Chromium (Cr)
Chromium improves hardenability and contributes to strength and wear resistance. The specified 0.90–1.20% chromium range gives 42CrMo4 its characteristic Cr-Mo alloy-steel behavior.
Chromium also supports the material’s response during heat treatment, helping thicker sections achieve useful mechanical properties.
Molybdenum (Mo)
Molybdenum plays an important role in hardenability and high-temperature strength. The 0.15–0.30% Mo range also helps the alloy maintain useful mechanical performance after tempering.
Because chromium and molybdenum work together, 42CrMo4 can provide a stronger hardening response than a comparable plain carbon steel.
Manganese (Mn)
Manganese contributes to hardenability and strength. The 0.60–0.90% range forms part of the balanced alloy design used in 42CrMo4.
Silicon (Si)
Silicon supports deoxidation during steelmaking and contributes to strength. EN 10083-3 limits silicon to a maximum of 0.40% for the commonly referenced 42CrMo4 composition.
Phosphorus and sulfur (P and S)
Phosphorus and sulfur require tighter control because excessive levels can negatively affect certain mechanical and processing characteristics. For 42CrMo4, EN 10083-3 specifies maximum limits of 0.025% phosphorus and 0.035% sulfur.
Do not confuse standard 42CrMo4 with 42CrMoS4. The “S” designation indicates a modified sulfur range intended to improve machinability under the relevant specification.
📊 4. 42CrMo4 Composition vs 4140 and SCM440
Buyers frequently compare 42CrMo4 with AISI 4140 and JIS SCM440 because all three belong to the Cr-Mo alloy steel family. However, their chemical requirements are not identical.
| Element | 42CrMo4, EN 10083-3 | 4140, common SAE/AISI specification | SCM440, JIS G4053 |
|---|---|---|---|
| C | 0.38–0.45% | About 0.38–0.43% | About 0.38–0.43% |
| Si | ≤ 0.40% | About 0.15–0.35% | About 0.15–0.35% |
| Mn | 0.60–0.90% | About 0.75–1.00% | 0.60–0.90% |
| Cr | 0.90–1.20% | About 0.80–1.10% | 0.90–1.20% |
| Mo | 0.15–0.30% | About 0.15–0.25% | 0.15–0.30% |
The comparison above illustrates why equivalent-grade charts require caution. The alloy concepts are similar, but the numerical limits can differ between standards. The 42CrMo4 values come from EN 10083-3, while the 4140 and SCM440 values depend on their respective specifications.
Is 42CrMo4 the same as 4140?
42CrMo4 and AISI 4140 are commonly treated as equivalent or closely corresponding grades for many engineering applications. However, they are not literally one universal specification. A buyer should compare the applicable standards before approving substitution.
Is 42CrMo4 the same as SCM440?
SCM440 also has a very similar alloy concept and commonly appears in international equivalent-grade tables. Nevertheless, JIS G4053 and EN 10083-3 define their own chemical requirements.
For normal procurement, a supplier can use the comparison as a starting point. For controlled engineering applications, the customer should approve the substitution based on the actual specification and MTC.
🔥 5. How Chemical Composition Affects 42CrMo4 Properties
The composition of 42CrMo4 directly influences its response to heat treatment and its final mechanical properties. However, chemistry alone does not determine the final hardness or strength.
Hardenability
Chromium, molybdenum, manganese, and carbon work together to improve hardenability. As a result, 42CrMo4 can develop useful strength through a significant section thickness when the supplier applies an appropriate heat-treatment process.
This characteristic makes the grade suitable for heavily loaded engineering components where a combination of core strength and toughness matters.
Strength and hardness
Carbon establishes much of the steel’s hardening potential, while Cr-Mo alloying supports the hardening response. After quenching and tempering, 42CrMo4 can achieve high strength with a controlled balance of toughness.
Actual mechanical properties depend on section size, heat-treatment parameters, cooling conditions, and the final tempering temperature. Therefore, buyers should never calculate final hardness from the chemical composition alone.
Machinability
42CrMo4 can offer reasonable machinability in suitable delivery conditions. Soft-annealed material generally machines more easily than hardened and tempered material.
If a project requires extensive machining, specify the delivery condition when requesting a quotation. The supplier can then recommend a suitable condition rather than supplying only the nominal grade.
📏 6. 42CrMo4 Steel Plate and Material Selection
When buyers search for 42CrMo4 steel plate, chemical composition represents only one part of the purchasing specification. Plate thickness, delivery condition, dimensional tolerance, surface condition, and testing requirements can also affect suitability.
Why thickness matters
Thicker sections cool more slowly during quenching than thin sections. This difference can influence the final microstructure and mechanical properties through the section.
Consequently, buyers should provide the actual plate thickness when asking a supplier about 42CrMo4 mechanical properties. A chemistry comparison without the product dimensions cannot fully determine performance.
Common procurement requirements
- 42CrMo4 / 1.7225 grade
- EN standard and applicable edition
- Plate thickness and dimensions
- Annealed or quenched-and-tempered condition
- Hardness requirement
- Tensile and yield strength requirements
- Ultrasonic testing, when required
- Mill Test Certificate
- Third-party inspection, when required
- Cutting and dimensional tolerance
For international purchasing, giving the supplier these details at the quotation stage reduces uncertainty and helps the buyer compare offers on the same technical basis.
42CrMo4 and cut-to-size supply
Some projects require standard plate dimensions, while others need material cut to a specified size. A supplier with saw cutting and machining capability can combine material supply with processing, reducing the number of external operations required after delivery.
🏭 7. 42CrMo4 Heat Treatment and Composition
The chemical composition establishes the hardening potential of 42CrMo4, but the heat-treatment process determines how the steel develops its final structure and mechanical properties.
Quenching
Industrial heat-treatment procedures commonly austenitize 42CrMo4 at a temperature appropriate to the material specification and section size, followed by controlled cooling. Published technical data commonly lists quenching temperatures around 820–850°C, depending on the specific procedure.
Because different product forms and standards can use different procedures, buyers should follow the applicable mill datasheet or heat-treatment specification rather than copy a single temperature into every application.
Tempering
After quenching, tempering reduces brittleness and allows engineers to establish the required balance between strength and toughness. Published 42CrMo4 data commonly gives tempering ranges around 540–680°C, although the final temperature should match the required mechanical properties and applicable specification.
Composition and heat-treatment response
A steel with the correct nominal grade but an incorrect delivery condition may not meet the customer’s requirements. For this reason, purchasing teams should treat chemical composition and heat treatment as two connected but separate specification checks.
The MTC should confirm the actual heat chemistry, while the inspection and mechanical-property data should confirm whether the supplied material meets the requested condition.
📋 8. How to Check 42CrMo4 Chemical Composition on an MTC
For procurement, the most reliable way to confirm 42CrMo4 chemical composition is to check the actual Mill Test Certificate supplied with the material.
Step 1: Confirm the grade
Check that the certificate identifies the material as 42CrMo4 and, where applicable, material number 1.7225.
Step 2: Check each element
Compare the reported C, Si, Mn, P, S, Cr, and Mo values with the applicable standard limits. Do not compare the certificate only with a generic website table if the purchase order specifies a particular standard edition.
Step 3: Check the product information
Verify the heat number, dimensions, delivery condition, and other identifying information. The chemical analysis should correspond to the supplied heat and product.
Step 4: Check mechanical requirements
Correct chemistry does not automatically prove that the material meets the required mechanical condition. Review hardness, tensile strength, yield strength, elongation, impact properties, or other requirements listed in the purchase specification.
For buyers comparing several suppliers, this process provides a much stronger basis for evaluation than comparing only the advertised grade name.
💰 9. Buying 42CrMo4 from a Steel Supplier
When purchasing 42CrMo4 internationally, buyers often focus first on price. However, the technical specification can significantly affect the final quotation.
For example, two suppliers may quote the same nominal grade but offer different thicknesses, delivery conditions, tolerances, testing levels, or processing services. These differences make a direct price comparison misleading.
What should a 42CrMo4 RFQ include?
- Grade: 42CrMo4 / 1.7225
- Applicable standard
- Product form
- Thickness, width, and length
- Quantity
- Delivery condition
- Hardness or mechanical requirements
- Ultrasonic testing requirements
- MTC requirements
- Cutting or machining requirements
- Destination and shipping terms
A clear RFQ allows the supplier to quote the correct material instead of offering a generic “42CrMo4 equivalent.”
42CrMo4 supplier selection
A reliable supplier should be able to explain the difference between the standard chemical composition, its own typical analysis, and the actual MTC chemistry. This distinction becomes particularly important when customers compare 42CrMo4 with 4140, SCM440, or other Cr-Mo grades.
For customized orders, the supplier should also confirm cutting tolerance, inspection requirements, packaging, and delivery schedule before production or shipment.
🏢 Otai Special Steel Advantages
- 10,000+ tons of steel stock supports international alloy steel supply.
- 42CrMo4 / SCM440 / 4140-related sourcing supports customers comparing international Cr-Mo grades.
- 20 saw cutting machines support fast and customized cutting services.
- CNC machining and grinding are available for customers requiring additional processing.
- Custom sizes and tolerances can be arranged according to project requirements.
- One-stop service covers cutting, machining, heat treatment, inspection, and export packaging.
- Ultrasonic testing and third-party inspection support are available for applicable orders.
- Export packaging can include bundled, wooden-box, and anti-rust protection according to order requirements.
- Otai has supplied tool steel and alloy steel to customers in 54+ countries since 1999.
❓ FAQ About 42CrMo4 Chemical Composition
1. What is the chemical composition of 42CrMo4?
Under the commonly referenced EN 10083-3 specification, 42CrMo4 contains C 0.38–0.45%, Si up to 0.40%, Mn 0.60–0.90%, P up to 0.025%, S up to 0.035%, Cr 0.90–1.20%, and Mo 0.15–0.30%.
2. What is the carbon content of 42CrMo4?
The specified carbon range for 42CrMo4 under EN 10083-3 is 0.38–0.45 wt.%. The nominal carbon level represented by the grade name is approximately 0.42%, but the actual standard allows a range.
3. How much chromium is in 42CrMo4?
42CrMo4 contains 0.90–1.20 wt.% chromium under the commonly referenced EN 10083-3 composition. Chromium contributes to hardenability and strength.
4. How much molybdenum is in 42CrMo4?
The molybdenum range is 0.15–0.30 wt.% under EN 10083-3. Molybdenum contributes to hardenability and supports the steel’s performance after heat treatment.
5. Is 42CrMo4 chemical composition the same as 4140?
No. 42CrMo4 and 4140 have similar Cr-Mo alloy designs and often appear as equivalent grades, but their standard composition limits are not identical. Buyers should compare the applicable specifications and actual MTC chemistry before approving substitution.
