Case-Hardening Steel

8620 · 1.6523

Also known as 21NiCrMo2 / SNCM220

Versatile Ni-Cr-Mo case-hardening steel popular in US specifications.

AISI 8620 (near EN 21NiCrMo2 / 1.6523) is a versatile nickel-chromium-molybdenum case-hardening steel widely used in US-spec components for gears, shafts and pins, giving a hard wear surface with a tough, ductile core.

International equivalents.

The same steel by country and standard — near matches; mill certificate governs.

8620 · AISI / SAE 21NiCrMo2 (1.6523) · EN SNCM220 · JIS

Chemical composition.

Indicative, % by weight per EN 10084. Mill certificate governs.

Element%
C 0.18 – 0.23
Si ≤ 0.40
Mn 0.70 – 0.90
Cr 0.40 – 0.60
Mo 0.15 – 0.25
Ni 0.40 – 0.70

Mechanical properties.

Indicative values for a reference section and heat-treatment condition. Actual properties vary with dimension and treatment, and are confirmed on the mill certificate.

Core tensile (Rm)
650 – 900 MPa (hardened)
Surface hardness
≈ 58 – 62 HRC
Hardness (annealed)
≤ 197 HB

Available forms.

Round bar Bright / cold-drawn bar Forged

Size: Ø 6 – 300 mm

Typical applications.

  • Gears & pinions
  • Shafts
  • Pins & bushings
  • Camshafts
Standards: EN 10084ASTM A29

FAQ.

What is 8620?

AISI 8620 (near EN 21NiCrMo2 / 1.6523) is a versatile nickel-chromium-molybdenum case-hardening steel widely used in US-spec components for gears, shafts and pins, giving a hard wear surface with a tough, ductile core.

Is 8620 the same as 21NiCrMo2?

Yes — 8620 and 21NiCrMo2, SNCM220 are matching designations for the same steel across different standards (EN, AISI/SAE, JIS, GB, former DIN). They are near equivalents and may differ slightly in chemistry, so the mill certificate governs the exact specification.

What are the international equivalents of 8620?

8620 corresponds to 8620 (AISI / SAE), 21NiCrMo2 (1.6523) (EN), SNCM220 (JIS). Equivalents are nearest matches by country/standard; the mill certificate governs the exact specification.

In which forms is 8620 available?

8620 is supplied as Round bar, Bright / cold-drawn bar, Forged, in Ø 6 – 300 mm.

What is 8620 used for?

Typical applications include Gears & pinions, Shafts, Pins & bushings, Camshafts.