Material 521


General Information for Material 521

Material Group H - Hardened Steel
Hardness 510.0 HB
Tensile Strength 1590-1800[N/mm^2]
Machinability Range 0% - 0%

Equivalent International Designations for Material 431 (HT)

Standard Name

Chemical Composition for Material 521

Element Amount
Nickel (Ni) 4%
Chromium (Cr) 2%
Molybdenum (Mo) 0.5%
Iron (Fe) 91.4%
Manganese (Mn) 1.2%
Silicon (Si) 0.5%
Carbon (C) 0.32%
Phosphorus (P) 0.025%
Sulfur (S) 0.005%


Cutting Speeds Recomendations for Material 521

Application Vc (m/min) Vc (SFM)

Important! The speed estimation is given for an ideal situation:
  • Most suitable carbide grade
  • Stable tool clamping
  • Stable workpiece clamping
  • Good quality raw material
  • A short overhang of the cutting tool.
  • Nominal hardness of the material.
  • etc.

Grade for Turning

Grade Coating Apps Range 05 10 15 20 25 30 35 40 45
No data available in table

Grade for Parting Off

Grade Coating Apps Range 05 10 15 20 25 30 35 40 45
No data available in table


Grade for Grooving

Grade Coating Apps Range 05 10 15 20 25 30 35 40 45
No data available in table

Grade for Milling (Indexable)

Grade Coating Apps Range 05 10 15 20 25 30 35 40 45
No data available in table

Recommended Insert Cutting Edge Geometry for Material 521