Steel Böhler S390 Annealed
Temper · default condition
also S390
Standard mill delivery condition for bar, plate and blanks; machine to shape here, then harden.
Values for the Annealed condition
Other Böhler S390 tempers and conditions
Böhler S390 is listed in 4 conditions; see the grade overview at Böhler S390.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hardened & triple tempered | The usual working hardness for hobs, milling cutters, broaches and form tools in difficult materials. | — | — | — | 67 HRC | — |
AnnealedDefaultThis page ≤ 340 HB (as-delivered bar/plate) | Standard mill delivery condition for bar, plate and blanks; machine to shape here, then harden. | 700 | 1,000 | 10 | 31 HRC | 3.4 % IACS |
Hardened & triple tempered | High austenitising temperature (~1180 °C) for maximum wear resistance and hot hardness; accept minimum toughness. | 2,000 | 2,100 | 0 | 69 HRC | 2.8 % IACS |
Hardened & triple tempered | Lower austenitising temperature; choose when edge chipping or interrupted cuts dominate over pure wear. | 2,100 | 2,400 | 0.5 | 65 HRC | 2.9 % IACS |
What is Böhler S390 Annealed?
Böhler S390 Annealed is Böhler S390 in the Annealed temper — standard mill delivery condition for bar, plate and blanks; machine to shape here, then harden. Böhler S390 Annealed has a yield strength of 700 MPa (102 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 81% of steel grades. Elongation at break is 10% and the elastic modulus is 230 GPa (33.4 Msi). Böhler S390 Annealed has a density of 8 g/cm³ (0.289 lb/in³), heavier than 95% of steel grades. It melts at 1,260°C (2,300 °F).
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
Limitations
- High embodied carbon — 5.5 kg CO₂/kg, worse than 97% of steel grades
- Difficult to machine — 25/100, worse than 93% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% of steel grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
Böhler S390 Annealed properties
Typical room-temperature values for Böhler S390 Annealed; 23 are specific to this condition. Other listed values are Böhler S390 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
Böhler S390 Annealed has a density of 8 g/cm³ (0.289 lb/in³), heavier than 95% of steel grades. It melts at 1,260°C (2,300 °F).
Mechanical17
Böhler S390 Annealed has a yield strength of 700 MPa (102 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 81% of steel grades. Elongation at break is 10% and the elastic modulus is 230 GPa (33.4 Msi).
Thermal5
Böhler S390 Annealed is rated for continuous service to 500°C (932 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
Böhler S390 Annealed conducts electricity at 3.4 % IACS, worse than 86% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of Böhler S390 Annealed takes about 70 MJ of energy and emits 5.5 kg of CO₂ — more than 97% of steel grades. Typical recycled content is 25%.
Manufacturability6
Böhler S390 Annealed's machinability is poor (25/100, worse than 93% of steel grades); weldability poor (20/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Böhler S390 Annealed
Is Böhler S390 easy to machine?
Machine only in the soft-annealed state with rigid setups, low speeds and carbide or coated-carbide tooling; after hardening the 4.8 % V carbides make CBN/diamond grinding the only practical route.
Can Böhler S390 be welded?
Not intended for structural welding; repair only by TIG/laser with matching PM-HSS filler, 450–500 °C preheat and immediate re-temper.
Can Böhler S390 be formed, bent or molded?
Hot forge 1100–900 °C with slow furnace cooling and soft anneal at 850–900 °C; no cold forming.
What surface finishes work on Böhler S390?
Vacuum harden 1150–1180 °C, triple temper 540–560 °C, then grind, lap and finish with TiAlN/AlCrN PVD, steam oxide or nitriding (thin case only).
Böhler S390 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 1.55 – 1.7 | 1.64 |
| Si | 0.3 – 0.8 | 0.6 |
| Mn | 0.2 – 0.5 | 0.3 |
| Cr | 4.6 – 5 | 4.8 |
| Mo | 1.8 – 2.2 | 2 |
| W | 10 – 11 | 10.5 |
| V | 4.6 – 5 | 4.8 |
| Cocobalt raises hot hardness and secondary hardening response | 7.5 – 8.5 | 8 |
| Fe | balance | — |
Böhler S390 Annealed — frequently asked
What is Böhler S390 Annealed used for?
Böhler S390 Annealed is typically used for high-performance drills, milling cutters and broaches. In short: high hot hardness PM-HSS; hardenable to 68–70 HRC; 4.8 % V carbide wear resistance.
What is the yield strength of Böhler S390 Annealed?
Böhler S390 Annealed has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is Böhler S390 Annealed easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of steel grades). Machine only in the soft-annealed state with rigid setups, low speeds and carbide or coated-carbide tooling; after hardening the 4.8 % V carbides make CBN/diamond grinding the only practical route.
Can Böhler S390 Annealed be welded?
Not readily — weldability is rated poor (20/100). Not intended for structural welding; repair only by TIG/laser with matching PM-HSS filler, 450–500 °C preheat and immediate re-temper.
What surface finishes work on Böhler S390 Annealed?
Vacuum harden 1150–1180 °C, triple temper 540–560 °C, then grind, lap and finish with TiAlN/AlCrN PVD, steam oxide or nitriding (thin case only).
Can Böhler S390 Annealed be formed, bent or molded?
Hot forge 1100–900 °C with slow furnace cooling and soft anneal at 850–900 °C; no cold forming.
What is the maximum service temperature of Böhler S390 Annealed?
Böhler S390 Annealed is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- BÖHLER S390 MICROCLEAN PM high speed steel data sheet — voestalpine BÖHLER Edelstahl (2022)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys (High-Speed Tool Steels) — ASM International (1990)
- ISO 4957 — Tool steels — ISO (2018)
- ASM Specialty Handbook: Tool Materials — ASM International (1995)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.