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; depends on dimension and heat treatment.

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 range: 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 is the European (EN) designation, while 21NiCrMo2, SNCM220 are the matching names used in other countries and standards (for example AISI/SAE in the USA, JIS in Japan, GB in China, former DIN in Germany). They are near equivalents and may differ slightly in chemistry; 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.