BLOG · JULY 2026
Steel Grades for Hot Forging: A Buyer's Reference Guide
When sourcing forged parts from China, you will encounter Chinese GB/T steel grades that may not have exact equivalents in your local standards. This reference guide maps the most common carbon and alloy steel grades across Chinese, European, and US designation systems — with practical guidance on how to specify the right grade for your forging application.
Carbon Steel Cross-Reference
| China (GB/T) | EU (EN 10083/10025) | USA (ASTM/AISI) | Germany (DIN) | Japan (JIS) | Typical Applications |
|---|---|---|---|---|---|
| Q235 | S235JR | A36 | St37-2 | SS400 | General structural, flanges, brackets |
| 45# | C45E / 1.1191 | 1045 | C45 | S45C | Shafts, gears, pins, general forgings |
| 20# | C22E / 1.1151 | 1020 | C22 | S20C | Carburized parts, low-stress components |
| 35# | C35E / 1.1181 | 1035 | C35 | S35C | Axles, bolts, moderately stressed parts |
| 55# | C55E / 1.1203 | 1055 | C55 | S55C | Wear-resistant parts, springs, rolls |
Alloy Steel Cross-Reference
| China (GB/T) | EU (EN) | USA (ASTM/AISI) | Germany (DIN) | Japan (JIS) | Key Features |
|---|---|---|---|---|---|
| 40Cr | 41Cr4 / 1.7035 | 5140 | 41Cr4 | SCr440 | General-purpose Cr steel, good strength |
| 42CrMo | 42CrMo4 / 1.7225 | 4140 | 42CrMo4 | SCM440 | High strength+Mo for hardenability |
| 20CrMnTi | 18CrMnTi similar | ~4820 | Not exact match | Not exact match | Carburizing grade, gear applications |
| 35CrMo | 34CrMo4 / 1.7220 | 4135 | 34CrMo4 | SCM435 | High-pressure vessels, heavy sections |
| 38CrMoAl | 41CrAlMo7 / 1.8509 | ~AMS 6470 | 34CrAlMo5 | SACM645 | Nitriding grade, wear-resistant shafts |
| 60Si2Mn | 61SiCr7 / 1.7108 | 9260 | 60SiCr7 | SUP6 | Spring steel, elastic components |
| GCr15 | 100Cr6 / 1.3505 | 52100 | 100Cr6 | SUJ2 | Bearing steel, rolling elements |
| 40Mn2 | ~40Mn4 / 1.5038 | 1340 | 40Mn4 | SMn438 | Track links, heavy-duty structural parts |
How to Choose the Right Steel Grade
When specifying a steel grade for your forging, consider these factors in order of priority:
- Mechanical requirements: What tensile strength, yield, and elongation does your design require?
- Section size: Larger cross-sections need higher hardenability (alloy grades like 42CrMo).
- Service temperature: For elevated temperatures, choose Mo-alloyed grades.
- Weldability: Carbon equivalent (CE) determines preheat requirements — lower is better for welding.
- Machinability: Higher carbon = harder to machine. Free-cutting additives (S, Pb) can help.
- Cost: Alloy grades cost 30-50% more than carbon steels. Only specify what you need.
Matching Grade to Forging Application
| Application | Recommended Grade(s) | Why This Grade |
|---|---|---|
| General structural (flanges, brackets) | Q235, 45# | Low cost, readily available, adequate strength |
| Automotive transmission (gears, shafts) | 40Cr, 42CrMo, 20CrMnTi | High fatigue strength, good hardenability |
| Connecting rods, crankshafts | 42CrMo, 40Cr | Excellent fatigue resistance, impact toughness |
| Suspension (steering knuckles) | 42CrMo, 40Cr | Impact resistance, ductility requirements |
| Excavator track links | 40Mn2, 35CrMo | Wear resistance, heavy-section hardenability |
| High-pressure valves | 35CrMo, 42CrMo | Pressure vessel integrity, elevated temp strength |
| Springs | 60Si2Mn | High elastic limit, fatigue resistance |
| Bearings | GCr15 | High hardness, wear resistance |
Practical Tips for Cross-Reference
- Always reference both your local standard AND the equivalent Chinese GB/T grade on the purchase order. This avoids confusion (e.g., "4140 (ASTM) = 42CrMo (GB/T)").
- Specify the required heat treatment condition (as-forged, normalized, quenched+tempered) as different heat treatments produce very different properties from the same grade.
- Request material certificates (EN 10204 3.1 or equivalent) to verify chemistry and mechanical properties.
- For critical applications, consider specifying an additional hardenability requirement (Jominy test per ISO 642 or ASTM A255).
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