440C Stainless Steel
1.4125
- EN1.4125
- ENX105CrMo17
- AISI440C
- UNSS44004
Martensitic stainless steel reaching the highest hardness within its class. High carbon and chromium content combine wear resistance with corrosion resistance; used in bearing and cutting applications.
01Material Properties
- Hardenable to 58–60 HRC
- Very good wear resistance
- Moderate to good corrosion resistance
- Magnetic
- Good dimensional stability at high hardness
02Applications
- Bearing balls, races and seats
- Valve seats and nozzles
- Knives and cutting tools
- Mold components requiring corrosion resistance
- Pump parts
03Delivery Condition
- Max. 285 HB, annealed.
04Heat Treatment
Typical values
- Soft annealing
- 800–850 °C; max. 285 HB
- Preheating
- 760–790 °C
- Hardening
- 1010–1065 °C; oil/air/pressurised gas
- Sub-zero
- Optional −75 °C (retained austenite)
- As-quenched hardness
- ≈ 58–61 HRC
- Tempering
- 150–200 °C → 57–59 HRC; avoid 425–565 °C
- Working hardness
- 56–60 HRC
Heat treatment cycle (schematic)
Tempering diagram (approximate)
Values are approximate and for information only; they vary with section size, heat and furnace conditions. Binding values are determined from the manufacturer’s data under laboratory conditions.
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