Case-Hardening Steel

18CrNiMo7-6 · 1.6587

Also known as former 17CrNiMo6

High-strength case-hardening steel for large, heavily loaded gears.

18CrNiMo7-6 (material 1.6587) is a high-strength chromium-nickel-molybdenum case-hardening steel for large, heavily loaded gears, shafts and bearings, offering deep hardening and excellent core toughness.

International equivalents.

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

18CrNiMo7-6 (1.6587) · EN 4320 (near) · AISI / SAE 17CrNiMo6 · former DIN

Chemical composition.

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

Element%
C 0.15 – 0.21
Si ≤ 0.40
Mn 0.50 – 0.90
Cr 1.50 – 1.80
Mo 0.25 – 0.35
Ni 1.40 – 1.70

Mechanical properties.

Indicative; depends on dimension and heat treatment.

Core tensile (Rm)
1100 – 1400 MPa (hardened)
Surface hardness
≈ 58 – 62 HRC
Hardness (annealed)
≤ 229 HB

Available forms.

Round bar Forged Bright / cold-drawn bar

Size range: Ø 16 – 600 mm

Typical applications.

  • Large industrial gears
  • Wind-turbine gearboxes
  • Heavy gear shafts
  • Bearings
Standards: EN 10084

FAQ.

What is 18CrNiMo7-6?

18CrNiMo7-6 (material 1.6587) is a high-strength chromium-nickel-molybdenum case-hardening steel for large, heavily loaded gears, shafts and bearings, offering deep hardening and excellent core toughness.

Is 18CrNiMo7-6 the same as former 17CrNiMo6?

Yes — 18CrNiMo7-6 is the European (EN) designation, while former 17CrNiMo6 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 18CrNiMo7-6?

18CrNiMo7-6 corresponds to 18CrNiMo7-6 (1.6587) (EN), 4320 (near) (AISI / SAE), 17CrNiMo6 (former DIN). Equivalents are nearest matches by country/standard; the mill certificate governs the exact specification.

In which forms is 18CrNiMo7-6 available?

18CrNiMo7-6 is supplied as Round bar, Forged, Bright / cold-drawn bar, in Ø 16 – 600 mm.

What is 18CrNiMo7-6 used for?

Typical applications include Large industrial gears, Wind-turbine gearboxes, Heavy gear shafts, Bearings.