Steel 1.2379 · hardness band
Steel 1.2379 Q&T 56-58 HRC
Properties of the Q&T 56-58 HRC condition, compared with the other 1.2379 tempers.
Slightly softer, tougher setting for tools with thin sections or heavy shock, where chipping is the main failure mode.
What is 1.2379 Q&T 56-58 HRC?
1.2379 Q&T 56-58 HRC is 1.2379 heat treated to Q&T 56-58 HRC — slightly softer, tougher setting for tools with thin sections or heavy shock, where chipping is the main failure mode. 1.2379 Q&T 56-58 HRC has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 1,800 MPa (261 ksi) — stronger than 60% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi). 1.2379 Q&T 56-58 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,420°C (2,588 °F). Annealed is the default condition FabDigit quotes; Q&T 56-58 HRC is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 75/100, better than 94% of steel grades
- Good corrosion resistance — 25/100, better than 91% of steel grades
Limitations
- Difficult to machine — 12/100, worse than 99% of steel grades
- Poor heat conductor — 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades
- Low electrical conductivity — 2.7 % IACS, worse than 96% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
1.2379 Q&T 56-58 HRC properties
Typical room-temperature values for 1.2379 Q&T 56-58 HRC — 9 properties are specific to this condition; the rest are grade-level values shared by every 1.2379 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1.2379 Q&T 56-58 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical12
1.2379 Q&T 56-58 HRC has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 1,800 MPa (261 ksi) — stronger than 60% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal5
1.2379 Q&T 56-58 HRC is rated for continuous service to 300°C (572 °F). It conducts heat at 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades. Thermal expansion is 10.9 µm/m·K (6.06 µin/in·°F).
Electrical3
1.2379 Q&T 56-58 HRC conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 91% of steel grades.
Sustainability4
Producing a kilogram of 1.2379 Q&T 56-58 HRC takes about 36 MJ of energy and emits 2.6 kg of CO₂ — more than 88% of steel grades. Typical recycled content is 40%.
Manufacturability8
1.2379 Q&T 56-58 HRC's machinability is not recommended (12/100, worse than 99% of steel grades); weldability poor (15/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1.2379 tempers and conditions
1.2379 is also supplied in 6 other conditions. The full side-by-side table is on the 1.2379 overview.
- AnnealedDefaultStandard as-delivered condition for bar, plate and precision-ground flat stock; machine here, then harden.480 MPa yield · 235 HB
- Q&T 60-62 HRCMaximum wear resistance and edge retention for blanking/punching thin, hard sheet; lowest toughness, use generous radii.2,100 MPa tensile
- Q&T 58-60 HRCThe most common working hardness: best balance of wear resistance and chipping resistance for general cold-work tooling.1,950 MPa tensile
- Q&T 56-58 HRCSlightly softer, tougher setting for tools with thin sections or heavy shock, where chipping is the main failure mode.1,800 MPa tensile
Working with 1.2379 Q&T 56-58 HRC
Is 1.2379 easy to machine?
Machine only in the annealed state with rigid setups, coated carbide and moderate speeds; the ~12 % carbide volume abrades tooling fast, and hardened tools are finished by grinding, EDM or hard-turning with CBN.
Can 1.2379 be welded?
Poor weldability — repair only, with 300–450 °C preheat, matched high-alloy filler, small stringer beads and an immediate temper; never weld in service without post-heat.
Can 1.2379 be formed, bent or molded?
Not a forming grade: hot work at 900–1080 °C with slow cooling and mandatory soft anneal at 830–870 °C; harden 1020–1040 °C, air/vacuum quench, then temper at least twice — allow ~0.05–0.1 % growth.
What surface finishes work on 1.2379?
Takes a fine mirror polish when hardened (ESR grades best); protect with oil, black oxide, hard chrome, nitriding or PVD TiCN/CrN since the alloy stains readily in humid air.
1.2379 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 | 1.45 – 1.6 | 1.53 |
| Si | 0.1 – 0.6 | 0.3 |
| Mn | 0.2 – 0.6 | 0.3 |
| Cr | 11 – 13 | 11.8 |
| Mo | 0.7 – 1 | 0.8 |
| V | 0.7 – 1 | 0.8 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
1.2379 Q&T 56-58 HRC — frequently asked
What is 1.2379 Q&T 56-58 HRC used for?
1.2379 Q&T 56-58 HRC is typically used for cold blanking and piercing dies, punches and die buttons, shear and slitter blades, thread-rolling dies, cold-forming and coining tooling and trim dies. In short: premium cold-work tool.
What is the yield strength of 1.2379 Q&T 56-58 HRC?
1.2379 Q&T 56-58 HRC has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 1,800 MPa (261 ksi) — stronger than 60% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 1.2379 Q&T 56-58 HRC easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 99% of steel grades). Machine only in the annealed state with rigid setups, coated carbide and moderate speeds; the ~12 % carbide volume abrades tooling fast, and hardened tools are finished by grinding, EDM or hard-turning with CBN.
Can 1.2379 Q&T 56-58 HRC be welded?
Not readily — weldability is rated poor (15/100). Poor weldability — repair only, with 300–450 °C preheat, matched high-alloy filler, small stringer beads and an immediate temper; never weld in service without post-heat.
What surface finishes work on 1.2379 Q&T 56-58 HRC?
Takes a fine mirror polish when hardened (ESR grades best); protect with oil, black oxide, hard chrome, nitriding or PVD TiCN/CrN since the alloy stains readily in humid air.
Can 1.2379 Q&T 56-58 HRC be formed, bent or molded?
Not a forming grade: hot work at 900–1080 °C with slow cooling and mandatory soft anneal at 830–870 °C; harden 1020–1040 °C, air/vacuum quench, then temper at least twice — allow ~0.05–0.1 % growth.
What is the maximum service temperature of 1.2379 Q&T 56-58 HRC?
1.2379 Q&T 56-58 HRC is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 1.2379 Q&T 56-58 HRC?
Yes — 1.2379 Q&T 56-58 HRC is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- EN ISO 4957 — Tool steels (X153CrMoV12) — ISO/CEN (2018)
- ASTM A681 — Alloy tool steels (Type D2) — ASTM (2015)
- GB/T 1299 — Tool and die steels (Cr12Mo1V1) — SAC (2014)
- Sverker 21 cold work tool steel — Uddeholm (2023)
- BÖHLER K110 datasheet — voestalpine Böhler Edelstahl (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- (SKD11/Cr12Mo1V1) — Mysteel / 1688 (2026)
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.