Steel Grade Datasheet
20NiCrMo2-2/ 1.6523 / 8620Ni-Cr-Mo Case-Hardening Steel
What is 8620 (20NiCrMo2-2) steel?
8620 (EN name 20NiCrMo2-2, Werkstoff No. 1.6523) is a nickel-chromium-molybdenum case-hardening (carburizing) steel. Compared with 16MnCr5, its nickel and molybdenum give a tougher and deeper-hardening core. After carburizing, the surface reaches 58–63 HRC — a hard, wear-resistant case over an impact-resistant tough core — making it the preferred material for heavy-duty transmission gears and drivetrain parts.
Chemical Composition
Cast analysis, % by weight (per the applicable EN standard)
| Element | Range (%) |
|---|---|
| C | 0.17–0.23 |
| Si | ≤ 0.40 |
| Mn | 0.65–0.95 |
| P | ≤ 0.025 |
| S | ≤ 0.035 |
| Cr | 0.35–0.65 |
| Mo | 0.15–0.25 |
| Ni | 0.40–0.70 |
Mechanical Properties (kör sertleştirilmiş (çekirdek) / blank-hardened core)
Values depend on ruling section / thickness (d).
| Section (mm) | Yield Re min (MPa) | Tensile Rm (MPa) | Elongation A min (%) |
|---|---|---|---|
| d ≤ 11 | 685 | 880–1180 | 8 |
| 11 < d ≤ 30 | 590 | 780–1080 | 9 |
| 30 < d ≤ 63 | 440 | 640–940 | 10 |
Hardness: +A (annealed): ≤ 217 HB (machinable) · Carburized surface: 58–63 HRC · Core: tougher than 16MnCr5 thanks to nickel
8620 / 20NiCrMo2-2 properties and use
International Equivalents
Values marked ≈ are nearest matches, not exact equivalents. Always confirm against the governing standard.
| System | Grade |
|---|---|
| EN | 20NiCrMo2-2 |
| W.-Nr. (DIN) | 1.6523 |
| AISI/SAE | 8620 |
| ASTM | A29 (8620) |
| JIS | SNCM220 |
| GOST | ≈ 20ХНМ (20KhNM) |
| BS (UK) | ≈ 805M20 (EN362) |
| GB (China) | ≈ 20CrNiMo |
Applications
- Heavy-duty transmission gears
- Differential and pinion gears
- Camshafts and shafts
- Carburized bearing components
- Sprockets and drive elements
- Heavy machinery drivetrain parts
Available Product Forms
Frequently Asked Questions
What is the difference between 8620 and 16MnCr5?+
8620 contains nickel and molybdenum, 16MnCr5 does not. Nickel raises core toughness and molybdenum raises hardenability — so 8620 is preferred for heavier-loaded and larger gears needing a tougher core. 16MnCr5 is more economical for small-to-medium gears.
What surface hardness does 8620 reach?+
After carburizing and quenching the surface is 58–63 HRC. The core, thanks to nickel-molybdenum, shows higher strength and toughness than unalloyed or chromium-only case-hardening steels.
Is 8620 the same as 20NiCrMo2-2?+
Yes; 8620 is the American (AISI/SAE) and 20NiCrMo2-2 the current European (EN) designation, material number 1.6523. The JIS equivalent is SNCM220. They are used interchangeably as the same nickel-chromium-molybdenum case-hardening steel.
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References & Standards
Values on this page are reference data compiled from the applicable EN standard; certified material properties are defined by the mill test certificate (EN 10204 3.1).