Ductile Iron Grade Comparison
The following table summarizes common ductile iron grades from various national standards. Please note that grades from different standards are not exactly equivalent. Always refer to the specific standard requirements for critical applications.
| China (GB/T1348) | USA (ASTM A536) | Japan (JIS G5502) | Germany (DIN 1693) | UK (BS EN 1563) | ISO (ISO 1083) | Min. Tensile Strength (MPa) | Min. Elongation (%) |
|---|---|---|---|---|---|---|---|
| QT400-18 | 60-40-18 | FCD400 | GGG-40 | GJS-400-18 | 400-18 | 400 | 18 |
| QT400-15 | 60-40-15 * | – | GGG-40 | GJS-400-15 | 400-15 | 400 | 15 |
| QT450-10 | 65-45-12 | FCD450 | GGG-45 | GJS-450-10 | 450-10 | 450 | 10 |
| QT500-7 | 80-55-06 | FCD500 | GGG-50 | GJS-500-7 | 500-7 | 500 | 7 |
| QT600-3 | – | FCD600 | GGG-60 | GJS-600-3 | 600-3 | 600 | 3 |
| QT700-2 | – | FCD700 | GGG-70 | GJS-700-2 | 700-2 | 700 | 2 |
| QT800-2 | 100-70-03 | FCD800 | – | GJS-800-2 | – | 800 | 2 |
| QT900-2 | 120-90-02 | – | – | GJS-900-2 | – | 900 | 2 |
Note: * Common non-standard grade, not directly listed in ASTM A536 but often available.
Key Information and Usage Advice
To ensure you use this information correctly, here are some important points:
• Grade Designation Logic
The naming conventions directly reflect key mechanical properties.
- China (GB): The grade “QT400-18” breaks down as follows: “QT” stands for “Qiu Tie” (Ball Iron), the first number (400) is the minimum tensile strength in MPa, and the second number (18) is the minimum elongation in %.
- USA (ASTM): The grade “65-45-12” represents minimum tensile strength (65 ksi), minimum yield strength (45 ksi), and minimum elongation (12%).
- Japan (JIS): The grade “FCD400” uses a prefix “FCD” and the number indicates the minimum tensile strength in MPa.
- Germany(DIN): The grade “GGG40” uses a prefix “GGG” and the number indicates the minimum tensile strength in MPa (e.g., GGG40 ≈ 400 MPa).
- UK (EN): The unified standard “EN-GJS-400-18” uses a prefix “EN-GJS” (where GJS is from the French “Graphite Sphéroïdal”), followed by tensile strength (MPa) and elongation (%).
• Correlations are Approximate
The correlations in the table are approximate equivalents based on similar mechanical properties. They are not fully identical due to potential differences in chemical composition, heat treatment requirements, and test specimen specifications. For critical design or procurement, you must consult the full specification of the target standard.
• Property and Microstructure
The properties of ductile iron are closely related to its matrix microstructure. For example, grades like QT400-18 have a predominantly ferritic matrix, giving them high ductility. Grades like QT700-2 have a pearlitic matrix, providing higher strength and hardness.
• Standard Validity
Please be aware that standards are periodically updated. Always confirm and use the latest active version of any standard for real-world engineering work.
Grey Cast Iron Grade Comparison
Here is a comparison table of common grey cast iron grades from major international standards. The grades are aligned based on comparable tensile strength
| China (GB/T 9439) | USA (ASTM -A48) | Japan (JIS G5501) | UK (BS 1452) | Germany (DIN 1691) | ISO (ISO 185) | Approx. Tensile Strength (MPa) |
|---|---|---|---|---|---|---|
| HT150 | Class 20 | FC150 | Grade 150 | GG15 | Grade 150 | ≥ 150 |
| HT200 | Class 30 | FC200 | Grade 220 | GG20 | Grade 220 | ≥ 200 |
| HT250 | Class 35 | FC250 | Grade 250 | GG25 | Grade 250 | ≥ 250 |
| HT300 | Class 40 | FC300 | Grade 300 | GG30 | Grade 300 | ≥ 300 |
| HT350 | Class 50 | FC350 | Grade 350 | GG35 | Grade 350 | ≥ 350 |
Key Points to Note
When using this cross-reference table, it’s helpful to keep the following in mind:
• Grade Designation Logic
The grade names typically indicate the material’s minimum tensile strength.
- China (GB/T 9439): “HT” stands for “Hui Tie” (Grey Iron). The number represents the minimum tensile strength in MPa (e.g., HT200 = 200 MPa).
- USA (ASTM-A48): “Class” refers to the minimum tensile strength in ksi (kilo-pounds per square inch). For example, Class 30 corresponds to 30 ksi, which is approximately 207 MPa.
- Japan (JIS G5501): “FC” is the prefix for grey iron, and the number indicates the minimum tensile strength in MPa (e.g., FC200 = 200 MPa).
- Germany (DIN EN1561): “GG” (from “Gusseisen mit Lamellengraphit”) is the prefix, followed by the approximate tensile strength in MPa (e.g., GG20 ≈ 200 MPa).
- ISO(ISO185)/ UK (BS): “Grade” refers to the minimum tensile strength in MPa.
• Approximate Equivalency
The table provides approximate equivalents based on tensile strength. However, full equivalence is not guaranteed because each standard may have different requirements for chemical composition, microstructure, wall thickness impact, and other mechanical properties like hardness. For critical applications, always consult the full specification of the relevant standard.
• Standard Updates
Standards are periodically revised. For instance, a new Chinese national standard, GB/T 45684-2025 (which modifies the international standard ISO 185:2020), is scheduled for implementation on December 1, 2025. It’s always best practice to use the latest active version of a standard.
Carbon Steel Casting Grade Comparison
Here is a comparison table of common carbon steel casting grades from major international standards. The grades are aligned based on comparable tensile strength and yield strength.
| Strength Grade (Approx.) | China (GB/T 11352) | USA (ASTM A27) | Japan (JIS G5101) | ISO (ISO 3755) | UK / Germany (EN 10293) |
|---|---|---|---|---|---|
| 200-400 MPa Level | ZG200-400 | Grade 60-30 | SC410 | CS 200-400 | GS-20Mn5 |
| 270-500 MPa Level | ZG270-500 | Grade 70-40 | SC450 | CS 270-500 | GS-26Mn5 |
| 310-570 MPa Level | ZG310-570 | Grade 80-50 | SC480 | CS 310-570 | — |
| 340-640 MPa Level | ZG340-640 | — | SC520 | — | — |
Key Points to Note
Grade Designation Logic
- China (GB) & ISO: The grade indicates minimum Yield Strength (MPa) – minimum Tensile Strength (MPa). E.g., ZG270-500 means Y.S. ≥ 270 MPa and T.S. ≥ 500 MPa.
- USA (ASTM): The grade indicates minimum Tensile Strength (ksi) – minimum Yield Strength (ksi). E.g., Grade 70-40 means T.S. ≥ 70 ksi (≈485 MPa) and Y.S. ≥ 40 ksi (≈275 MPa).
- Japan (JIS): The number approximates the minimum Tensile Strength (MPa). E.g., SC450 has a T.S. ≥ 450 MPa.
- Europe (EN): Grades are based on chemical composition. E.g., GS-20Mn5 signifies Cast Steel with ~0.20% Carbon and ~1.5% Manganese.
Correlation
The grades listed in the same row are approximate equivalents based on similar mechanical properties and are not fully identical. Always consult the full specification of the relevant standard for critical applications.
Standard Scope
Please note that the European standard EN 10293 is primarily for pressure-containing components and has stricter chemical composition requirements. Therefore, its grades do not have a direct one-to-one correspondence with those from general engineering standards like ASTM A27 or GB/T 11352.
Low-Alloy Steel Casting Grade Comparison
Here is a comparison table of common low-alloy steel casting grades from major international standards. The grades are aligned based on comparable mechanical properties or chemical composition.
| Strength Grade / Alloy Type | China (GB/T 11352) | USA (ASTM A148) | Japan (JIS G5102) | ISO (ISO 4997) | EN/DIN 10293 | Typical Tensile Strength (MPa) | Typical Application |
|---|---|---|---|---|---|---|---|
| 500–700 MPa (Medium Strength) | ZG35SiMn | 90-60-02 | SMn438 | LAS 500-7 | GS-25CrMo4 | 500–650 | General machinery, housings |
| 700–900 MPa (High Strength) | ZG40Cr, ZG42CrMo | 105-85-02 | SCM435, SCM440 | LAS 700-2 | GS-34CrMo4 | 750–850 | Shafts, gears, high-load parts |
| 900–1100 MPa (Extra High Strength) | — | 120-95-02 | — | LAS 900-2 | GS-42CrMo4 | 900–1000 | Heavy-duty shafts, pressure parts |
| High Toughness Alloy | ZG20CrMo | — | — | — | GS-20CrNiMo7 | High impact toughness | Impact-loaded structural parts |
Key Notes for Low-Alloy Steel Table
Grade Designation Logic
- China (GB): “ZG” + principal alloying elements (e.g., Cr: Chromium, Mo: Molybdenum, Mn: Manganese).
- USA (ASTM): Grades indicate min. T.S. (ksi) – min. Y.S. (ksi) – min. Elongation %.
- Japan (JIS): Prefix indicates alloy type: “SCM” = Cr-Mo steel; “SMn” = Mn steel.
- Europe (EN): Grades are based on chemical composition (e.g., 34CrMo4: ~0.34% C, Cr-Mo alloy).
Correlation
Equivalents are approximate, based on similar strength levels or alloy types. Selection for critical applications must be based on the full requirements of the relevant standard.
Stainless Steel Casting Grade Comparison
Here is a comparison table of common stainless steel casting grades from major international standards. The grades are aligned based on comparable mechanical properties or chemical composition.
| Microstructure / Corrosion Resistance | China (GB/T 2100) | USA (ASTM A743/A744) | Japan (JIS G5121) | ISO (ISO 11972) | EN/DIN 10283 |
|---|---|---|---|---|---|
| Martensitic (13Cr) | ZG06Cr13Ni4Mo | CA6NM | SCS1 | GX4CrNi13-4 | G-X6CrNi13-4 |
| Austenitic (Standard 18-8) | ZG06Cr19Ni9 | CF8, CF3 | SCS13, SCS14 | GX5CrNi19-10 | G-X6CrNi18-10 |
| Austenitic (Mo-Alloyed) | ZG06Cr19Ni10Mo2 | CF8M, CF3M | SCS16, SCS17 | GX5CrNiMo19-11-2 | G-X6CrNiMo17-12-2 |
| Duplex Austenitic-Ferritic | ZG03Cr22Ni5Mo3N | CD4MCu, CD3MN | SCS21 | GX2CrNiMoN19-11-2 | G-X2CrNiMoN18-14-3 |
Key Notes for Stainless Steel Table
Grade Designation Logic
- China (GB) & ISO & Europe (EN): Grades specify exact chemical composition (Cr-Ni-Mo content).
- USA (ASTM): “C” = Corrosion-resistant. “F” = Austenitic; “A” = Martensitic. The number indicates composition variation (e.g., CF8M has Molybdenum).
- Japan (JIS): “SCS” = Stainless Cast Steel. Grades are generally equivalent to ASTM grades (e.g., SCS13 ≈ CF8).
Microstructure & Properties
The microstructure (Martensitic, Austenitic, Duplex) fundamentally determines the mechanical properties and corrosion resistance of the stainless steel.
Die Casting Aluminum Alloys Comparison
Here is a comparison table of common die-casting aluminum alloy grades from major international standards. The grades are mainly aligned based on comparable chemical composition.
| Alloy Series | China (GB/T 15115) | USA (ASTM B85) | Japan (JIS H5302) | Europe (EN 1706 / DIN 1725) | ISO (ISO 3522) | Typical Mechanical Properties (As-Cast) |
|---|---|---|---|---|---|---|
| Al-Si | YL102 (YZA1Si12) | 413.0 | ADC1 | EN AC-44100 (AlSi12) | Al-Si12 | UTS ≈ 130–170 MPa, Elongation ≈ 1–3% |
| Al-Si-Mg | YL104 (YZA1Si10Mg) | 360.0 | ADC3 | EN AC-43000 (AlSi10Mg) | Al-Si10Mg | UTS ≈ 230–280 MPa, Elongation ≈ 3–6% |
| Al-Si-Cu | YL112 (YZA1Si9Cu4) | 380.0 | ADC10 | EN AC-46000 (AlSi9Cu3(Fe)) | Al-Si9Cu3(Fe) | UTS ≈ 200–240 MPa, Elongation ≈ 1–3% |
| Al-Si-Cu | YL113 (YZA1Si11Cu3) | 383.0 | ADC12 | EN AC-47100 (AlSi11Cu2(Fe)) | Al-Si11Cu2(Fe) | UTS ≈ 190–230 MPa, Elongation ≈ 1–2% |
| Al-Mg | YL302 (YZA1Mg5Si1) | 518.0 / 535.0 | ADC5 / ADC6 | EN AC-51300 (AlMg5) / EN AC-51100 (AlMg9) | Al-Mg5Si1 | UTS ≈ 220–260 MPa, Elongation ≈ 6–10% |
Key Notes for Using the Table
Approximate Equivalency
The grades listed in the table are approximate equivalents. This equivalence is primarily based on similar chemical compositions. However, there can be differences in limits for impurity elements (like Iron), heat treatment rules, and specified mechanical properties. For critical applications, consulting the full specification of the relevant standard is essential.
ISO Grade Designation
The ISO 3522 standard for cast aluminum alloys uses a naming system based directly on chemical composition. The format is typically Al-[Principal alloying element][% content], such as Al-Si12 for an alloy with approximately 12% Silicon. This makes ISO grades very intuitive to understand.
China’s GB Grade Designation
In the Chinese standard, “YL” stands for “Ya Zhu”, meaning Die Casting. The numbers following it are sequential identifiers.
Specify the Standard
For procurement or design, always specify the alloy grade alongside the standard to which it is supplied (e.g., GB/T 15115-2024 or ISO 3522).
Cast Aluminum Alloys Grade Comparison
The table below lists the main cast aluminum alloy grades specified in China’s GB/T 1173-2013 standard, along with their approximate equivalent grades in ISO (International Organization for Standardization), U.S., European, and Japanese standards.
| China (GB/T 1173-2013) | Alloy Series | Japan (JIS H5202) | USA (AA/ASTM) | Europe (EN 1706) | ISO (ISO 3522) |
|---|---|---|---|---|---|
| ZL101A | Al-Si-Mg | AC4C | 356.0 | EN AC-42100 | Al-Si7Mg0.3 |
| ZL104 | Al-Si-Mg | AC4A | A360.0 | EN AC-43000 | Al-Si9Mg |
| ZL105 | Al-Si-Cu-Mg | — | 355.0 | — | Al-Si5Cu1Mg |
| ZL114A | Al-Si-Mg | — | A357.0 | — | Al-Si7Mg0.6 |
| ZL201 | Al-Cu-Mn | — | A206.0 | EN AC-21000 | Al-Cu4Ti |
| ZL203 | Al-Cu-Mn | — | 295.0 | — | — |
| ZL205A | Al-Cu-Mn-Cd-V | — | 201.0 | — | — |
| ZL301 | Al-Mg | — | 520.0 | EN AC-51200 | Al-Mg10 |
| ZL303 | Al-Mg-Si | — | — | EN AC-51300 | Al-Mg5Si1 |
| ZL401 | Al-Zn-Si | — | 712.0 | — | — |
| ZL402 | Al-Zn-Mg | — | 713.0 | — | — |
Important Usage Instructions & Recommendations
To help you use this comparison table more accurately, the following key information requires special attention:
Grade Naming Logic
Understanding the naming rules of different standards will help you identify materials more effectively:
- China (GB/T): The prefix “ZL” stands for “cast aluminum” (in Chinese). The first digit (1-4) indicates the alloy series (1 = Al-Si series, 2 = Al-Cu series, 3 = Al-Mg series, 4 = Al-Zn series). The suffix “A” usually denotes a high-quality alloy (with higher purity and fewer impurities).
- Japan (JIS): Cast aluminum alloy grades often start with “AC”. For example, AC4C is a common Al-Si-Mg cast aluminum alloy in the JIS standard.
- United States (AA): Cast aluminum alloys are identified by a three-digit number followed by “.0” (e.g., xxx.0), which distinguishes them from wrought aluminum alloy designations.
- Europe (EN): Grades follow the format “EN AC-XXXXX”, and a chemical name is often appended afterward to facilitate intuitive understanding of the alloy’s main composition.
- International (ISO): Grade designations directly reflect the alloy’s main chemical composition and approximate content. For instance, “Al-Si7Mg” indicates an Al-Si alloy containing approximately 7% silicon and a small amount of magnesium.
Notes on Approximate Equivalence
The grade correspondences in the table are approximate equivalents, primarily based on similar chemical compositions and basic mechanical properties. However, it should be noted that different standards may have minor differences in aspects such as impurity element content (e.g., allowable upper limits of iron or copper) and heat treatment systems. These differences may affect the final performance of the material (e.g., corrosion resistance, workability). Therefore, for critical product design, bulk procurement, or quality inspection, you must refer to and strictly comply with the latest complete text of each specific standard to avoid deviations caused by relying solely on this comparison table.
Critical Importance of Heat Treatment Conditions
The performance of cast aluminum alloys (e.g., strength, hardness, toughness) largely depends on their heat treatment conditions, with common conditions including T5 (artificial aging) and T6 (solution treatment + full artificial aging). When comparing grades across different standards, you must ensure that the grades are compared under the same heat treatment conditions; otherwise, their performance data will not be comparable. For example, the strength of the same grade in the T5 condition may be lower than in the T6 condition. Ignoring differences in heat treatment conditions during comparison may lead to incorrect material selection.
Scope of Application of the Standard
Please note that GB/T 1173-2013 mainly applies to aluminum alloy castings produced by sand casting, permanent mold casting, investment casting (lost-wax casting), and shell molding. It generally does not cover die-cast aluminum alloys (e.g., ADC12 in the Japanese JIS standard). If you need to find the grade correspondences for die-cast aluminum alloys, you should refer to specialized standards for die-casting processes, such as GB/T 15115 (China’s die-cast aluminum alloy standard) and ASTM B85 (U.S. die-cast aluminum alloy standard).
Copper and Copper Alloy Grades Comparison
Below is a comparison table of common copper and copper alloy grades from major international standards. The table covers pure copper, brass (Cu-Zn), and leaded brass, with corresponding grades from China (GB), the USA (ASTM/UNS), Japan (JIS), the UK (BS), Germany (DIN), and ISO.
| Material Type | Common Names | China (GB/T 5231) | USA (ASTM/UNS ASTM B152/B153/B169) | Japan (JISH3100 /H3250/ H3260/H3300) | UK (BS 2870) | Germany (DIN EN 1652) | ISO(ISO 1338) |
|---|---|---|---|---|---|---|---|
| Pure Copper (≥99.90% Cu) | T2 | C11000 | C1100 | C102 | ECu-58 | Cu-ETP | |
| Oxygen-Free Copper | TU1 | C10200 | C1020 | — | OF-Cu | — | |
| Phosphorus-Deoxidized Copper | TP2 | C12200 | C1220 | — | SW-Cu / SF-Cu | — | |
| Brass (Cu-Zn) | CuZn30, CuZn33 | H68 / H70 | C26000 | C2600 | CZ106 | CuZn30 | CuZn30 |
| Brass (Cu-Zn) | CuZn36, CuZn37 | H62 / H60 | C27400 / C27200 | C2720 | CZ108 | CuZn37 | CuZn37 |
| Leaded Brass | CuZn36Pb1.5, CuZn39Pb3 | HPb59-1 | C37800 | C3710 | CZ122 | CuZn39Pb3 | CuZn39Pb3 |
Notes for Using the Table
Grade Designation Logic
- China (GB): Uses a categorical system. Prefixes indicate type:
- T = Pure copper (e.g., T2).
- H = Brass (Huangtong), followed by approximate copper content (e.g., H62 ≈ 62% Cu).
- HPb = Leaded brass.
- USA (ASTM/UNS): Uses a numeric code system (UNS). For copper alloys, this is typically a C prefix followed by five digits (e.g., C11000 for pure copper).
- Japan (JIS): Similar to the U.S. system, using letter + numeric codes (e.g., C1100, C2600).
- Europe (BS, DIN, ISO): Often uses chemical composition-based designations. For example:
- CuZn30 indicates a brass with ~30% zinc.
- CuZn39Pb3 indicates a brass with ~39% zinc and ~3% lead.
- DIN may also include material number codes (e.g., 2.0335).
Approximate Equivalency
The table provides approximate equivalents based on similar chemical compositions and applications. These grades are not fully identical—differences may exist in permitted impurity levels, mechanical properties, or processing requirements. Always consult the specific standard for critical applications.
Key Applications
- Pure Coppers (T2, C11000, etc.): Electrical conductors, roofing, plumbing tubes.
- Brasses (H68, C26000, etc.): Cartridge cases, springs, architectural trim, fasteners.
- Leaded Brasses (HPb59-1, C37800, etc.): Excellent machinability; used for valves, fittings, gears.
Missing Grades / Specific Needs
Some common grades (e.g., CZ127 brass in BS, CuZn39Pb2 in DIN) are not listed here due to space constraints. If you need details on a specific alloy type (e.g., bronze, copper-nickel) or a particular grade, feel free to
Contact our material engineers!
Low Carbon (Structural) Steel Grade Comparison
Here’s a combined table that includes both low-carbon steels (by carbon content) and low-carbon structural steels.
| Category / Carbon Content | China (GB/T 699/700) | USA (AISI SAE J1086/ ASTM A36/A283) | Japan (JIS G4051 /G3101) | UK (BS 970 / EN 10025) | Germany (DIN EN10083 / EN 10025) | ISO (ISO 630 / 683) | Typical Applications |
|---|---|---|---|---|---|---|---|
| Low Carbon Steel ~0.10% C | 10# | 1010 | S10C | – | C10E | C10E | Carburized parts, low-stress pins |
| Low Carbon Steel ~0.15% C | 15# | 1015 | S15C | 080M15 | C15E | C15E | Bolts, rods, cold heading parts |
| Low Carbon Steel ~0.20% C | 20# | 1020 | S20C | 080M20 | C22E | C22E | Shafts, carburized gears |
| Low Carbon Steel ~0.25% C | 25# | 1025 | S25C | – | C25E | C25E | Forged machine parts |
| Low-Carbon Structural Steel | Q195 | A283 Grade D | – | – | – | ISO 630 E195 | Wire rods, light sections |
| Low-Carbon Structural Steel | Q215 | A283 Grade C | – | – | – | ISO 630 E215 | Tubes, bars, light structures |
| Low-Carbon Structural Steel | Q235 | A36 | SS400 | S235JR | S235JR | ISO 630 E235 | Beams, plates, building frames |
| Low-Carbon Structural Steel | Q275 | – | – | S275JR | S275JR | ISO 630 E275 | Heavy structural members |
Key Notes
- Q-series steels in China are named for their minimum yield strength (e.g., Q235 → 235 MPa).
- ASTM A36 and SS400 are the most commonly referenced equivalents internationally for Q235.
- ISO 630 provides standardized grades E195, E215, E235, and E275 that correspond closely to the Chinese Q-series.
Medium Carbon Steel Grade Comparison
The table below lists the approximate equivalent grades of common medium carbon steels in the standards of China, the United States, Japan, the United Kingdom, Germany, and ISO. Please note that different standards have varying requirements for chemical composition and impurity content, so the corresponding relationships are approximate.
| Grade (by Category) | China (GB/T 699) | USA (AISI/SAE J1086) | Japan (JIS G4051) | UK (BS 970) | Germany (DIN/EN 10083) | ISO (ISO 683) | Typical Applications |
|---|---|---|---|---|---|---|---|
| ~0.30% C | 30# | 1030 | S30C | 080M30 | C30E | C30E | Forged levers, shafts |
| ~0.35% C | 35# | 1035 | S35C | 080M36 | C35E | C35E | Axles, pins, bolts |
| ~0.40% C | 40# | 1040 | S40C | 080M40 | C40E | C40E | Crankshafts, gears |
| ~0.45% C | 45# | 1045 | S45C | 080M46 | C45E | C45E | Most common medium carbon steel for machinery |
| ~0.50% C | 50# | 1050 | S50C | 080M50 | C50E | C50E | Higher strength parts, springs after heat treatment |
High Carbon Steel Grade Comparison
The table below lists the approximate equivalent grades of common high carbon steels in the standards of China, the United States, Japan, the United Kingdom, Germany, and ISO.
| Grade (by Category) | China (GB/T 699) | USA (AISI/SAE J1086) | Japan (JIS G4051) | UK (BS 970) | Germany (DIN/EN 10083) | ISO (ISO 683) | Typical Applications |
|---|---|---|---|---|---|---|---|
| ~0.55% C | 55# | 1055 | S55C | 080M55 | C55E | C55E | Wear-resistant parts |
| ~0.60% C | 60# | 1060 | S60C | 080M60 | C60E | C60E | Blades, hammers |
| ~0.65% C | 65# | 1065 | S65C | 080M65 | C67E | C67E | Springs, knives |
| ~0.70% C | 70# | 1070 | S70C | – | C70 | C70 | High-strength tools |
Introduction to Grade Naming Rules
Understanding the naming logic of different standards will help you better identify and use these grades:
- China (GB/T): Grades usually consist of Arabic numerals, representing the ten-thousandth of the average carbon content of the steel. For example, “45” indicates a quality carbon structural steel with an average carbon content of 0.45%.
- United States (AISI/SAE): A four-digit numbering system is adopted. The first two digits “10” indicate carbon steel; the last two digits represent the ten-thousandth of the average carbon content of the steel. For example, “1045” refers to a carbon steel with an average carbon content of 0.45%.
- Japan (JIS): Grades start with “S”, which stands for carbon steel. The following numbers indicate the minimum tensile strength or average carbon content. For carbon steel for structural use (e.g., S25C, S45C), the numbers usually represent the average carbon content.
- Europe (BS, DIN/EN): European standards are gradually being unified.
- United Kingdom (BS): Various systems have been used historically, such as the “EN” series (e.g., EN15A) and numerical codes (e.g., 080A47). Modern standards tend to adopt unified European EN standards.
- Germany (DIN/EN): Grades often start with “C”, followed by numbers representing the ten-thousandth of the average carbon content (e.g., C45). Meanwhile, each grade is accompanied by a material number (e.g., 1.1191).
- ISO: The grade representation method is similar to that of European EN standards.
Important Usage Recommendations
When using this comparison table, the following points require special attention:
Approximate Equivalence
The corresponding relationships in the table are approximate, mainly based on similar carbon content and mechanical properties. Different standards may have differences in the content of elements such as manganese and silicon, as well as the upper limits of impurities such as phosphorus and sulfur. These differences can affect the hardenability, processability, and final service performance of the material. For material selection of critical components, be sure to refer to and comply with the complete original text of the specific standard.
Heat Treatment Conditions
The performance of medium carbon steel largely depends on its heat treatment conditions (e.g., annealing, normalizing, quenching, and tempering). When comparing grades from different standards, it is necessary to ensure that they are compared under the same heat treatment conditions.
Standard Updates
Engineering and technical standards are continuously updated. For example, the British grade “EN16” has been replaced by “605M36”. In practical work, be sure to confirm and use the latest valid version of the standard.
Alloy Structural Steel Grades Comparison
Here is a comprehensive cross-reference table for common alloy structural steel grades from the Chinese standard GB/T 3077-2015. Each row represents a specific grade, and columns indicate equivalent grades from other countries or regions where applicable.
| Steel Grade | China (GB/T 3077-2015) | USA (AISI/SAE J404 /J412 /J770) | Japan (JIS G4053) | UK (BS 970) | Germany (DIN EN 10083) | ISO (ISO 683) |
|---|---|---|---|---|---|---|
| 42CrMo | 42CrMo | 4140 | SCM440 | 708M40 | 1.7225 | 42CrMo4 |
| 35CrMo | 35CrMo | 4130 | SCM430 | 708A25 | 1.7218 | 35CrMo4 |
| 40Cr | 40Cr | 5140 | SCr440 | 817M40 | 1.7035 | 40Cr4 |
| 20CrMo | 20CrMo | 5120 | SCM220 | 20CD4 | 1.7218 | 20CrMo4 |
| 30CrMo | 30CrMo | 4130 | SCM430 | 708A25 | 1.7218 | 30CrMo4 |
| 20CrNiMo | 20CrNiMo | 8620 | SNCM220 | 20CrNiMo | 1.6523 | 20CrNiMo4 |
Key notes to this table:
- 35CrMo vs. AISI 4130 / 30CrMo vs. 4130: Although often used as equivalents, 35CrMo and 30CrMo have slightly higher carbon content than AISI 4130. When substituting, adjust heat treatment to achieve the target mechanical properties.
- 20CrMo vs. 5120: AISI 5120 typically contains little or no Mo, so for high-strength or elevated-temperature applications, SCM220 or ISO 20CrMo4 are better matches.
- 40Cr vs. 5140 / 817M40: 5140 may have slightly higher C content, and 817M40 is closer to 4140. Check hardenability and toughness requirements before substitution.
- International Standards: Chemical composition limits may vary slightly between GB/T, AISI, JIS, EN/DIN, and ISO. Always confirm the exact specification (chemical range and mechanical properties) before final material selection.
Explanation of Standards
China GB/T 3077-2015 is the Chinese national standard for Alloy Structural Steel. It defines the chemical composition, heat treatment conditions, and mechanical properties of alloy steels. Grades such as 42CrMo, 35CrMo, and 20CrMo are widely used in China for high-strength, quenched-and-tempered applications.
USA (AISI/SAE J404/J412/J770): These specifications provide unified numbering systems for alloy steels, such as 4140, 4130, and 8620. They are commonly used across North America in the automotive industry, heavy equipment manufacturing, and general engineering.
Japan JIS G4053 is the Japanese standard for Structural Alloy Steels for Machinery. This specification covers grades such as SCM220, SCM430, SCM440, and SNCM220. JIS standards are known for strict composition limits and guaranteed mechanical properties, making them popular in precision applications and export-oriented manufacturing.
UK BS 970 standard specifies Wrought Steels for Mechanical and Allied Engineering Purposes. Traditional designations like 708M40 are still commonly found in engineering drawings, even though BS 970 has largely been replaced by the European standard EN 10083.
DIN EN 10083, which is the harmonized European specification for Steels for Quenching and Tempering. It covers grades such as 1.7225 (42CrMo4) and 1.7218 (35CrMo4) and provides detailed guidance on heat treatment conditions and expected mechanical properties.
ISO 683 is the international standard that unifies the classification of Heat-Treatable Steels, Alloy Steels, and Free-Cutting Steels. It provides globally recognized equivalents, such as ISO 42CrMo4, ensuring compatibility in cross-border engineering projects and international supply chains.
