Steel 6CrMnSi2Mo1V Q&T 57-59 HRC
Hardness band
GB 6CrMnSi2Mo1V
Q&T 57-59 HRC = oil quench + low temper
Maximum hardness / wear resistance for cold shear blades and punches where impact is moderate.
Values for the Q&T 57-59 HRC condition
Other 6CrMnSi2Mo1V tempers and conditions
6CrMnSi2Mo1V is listed in 6 conditions; see the grade overview at 6CrMnSi2Mo1V.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault spheroidize annealed, as supplied | Standard mill supply condition for bar and flat: soft enough to machine tools before hardening. | 490 | 780 | 20 | 217 HB | — |
900 °C air cool (pre-treatment before re-annealing) | Grain-refining pre-treatment on forgings; not a delivery or service condition, always followed by annealing. | 800 | 1,150 | 10 | 37 HRC | 2.7 % IACS |
Oil quench + temper ~380–420 °C | Toughest usable condition — pick for riveting sets, heavy shock punches and hot-shear-free impact tooling. | 1,480 | 1,750 | 8 | 51 HRC | — |
Oil quench + temper ~250–300 °C | Best all-round hardness/toughness balance for chisels, punches and pneumatic tool parts. | 1,650 | 1,950 | 5 | 55 HRC | — |
Q&T 57-59 HRCThis page Oil quench + low temper | Maximum hardness / wear resistance for cold shear blades and punches where impact is moderate. | 1,800 | 2,150 | 3 | 58 HRC | — |
As-Quenched 60–62 HRC | Intermediate condition only — must be tempered immediately to avoid quench cracking. | 2,000 | 2,400 | 1 | 61 HRC | 2.5 % IACS |
What is 6CrMnSi2Mo1V Q&T 57-59 HRC?
6CrMnSi2Mo1V Q&T 57-59 HRC is 6CrMnSi2Mo1V heat treated to Q&T 57-59 HRC — maximum hardness / wear resistance for cold shear blades and punches where impact is moderate. 6CrMnSi2Mo1V Q&T 57-59 HRC has a yield strength of 1,800 MPa (261 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Elongation at break is 3% and the elastic modulus is 207 GPa (30 Msi). 6CrMnSi2Mo1V Q&T 57-59 HRC has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 92% of steel grades. It melts at 1,400°C (2,552 °F). Annealed is the default condition FabDigit quotes; Q&T 57-59 HRC is available on request or by drawing note.
Advantages
- High strength — 1,800 MPa (261 ksi), better than 99% of steel grades
Limitations
- Difficult to machine — 8/100, worse than 100% of steel grades
- Limited ductility — 3%, worse than 99% of steel grades
- Limited service temperature — 150°C (302 °F), worse than 99% of steel grades
- Poor heat conductor — 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades
- High embodied carbon — 2.8 kg CO₂/kg, worse than 90% of steel grades
6CrMnSi2Mo1V Q&T 57-59 HRC properties
Typical room-temperature values for 6CrMnSi2Mo1V Q&T 57-59 HRC; 13 are specific to this condition. Other listed values are 6CrMnSi2Mo1V reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
6CrMnSi2Mo1V Q&T 57-59 HRC has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 92% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical12
6CrMnSi2Mo1V Q&T 57-59 HRC has a yield strength of 1,800 MPa (261 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Elongation at break is 3% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
6CrMnSi2Mo1V Q&T 57-59 HRC is rated for continuous service to 150°C (302 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).
Electrical2
6CrMnSi2Mo1V Q&T 57-59 HRC has an electrical resistivity of 6×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 6CrMnSi2Mo1V Q&T 57-59 HRC takes about 36 MJ of energy and emits 2.8 kg of CO₂ — more than 89% of steel grades. Typical recycled content is 40%.
Manufacturability8
6CrMnSi2Mo1V Q&T 57-59 HRC's machinability is not recommended (8/100, worse than 100% of steel grades); weldability poor (20/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6CrMnSi2Mo1V Q&T 57-59 HRC
Is 6CrMnSi2Mo1V easy to machine?
Machine only in the annealed state (≈200 HB, ~55 % of AISI 1212) with rigid setups and sharp carbide/HSS tooling; after hardening only grinding and EDM are practical, and EDM'd surfaces should be stress-relieved.
Can 6CrMnSi2Mo1V be welded?
Poor weldability — repair welding only with matching or low-hydrogen tool-steel filler, preheat 300–350 °C, keep interpass temperature, and temper immediately at the part's tempering temperature to avoid cracking.
Can 6CrMnSi2Mo1V be formed, bent or molded?
Hot forge 1050 → 900 °C with slow furnace cooling and mandatory anneal; cold forming is impractical, so shapes are machined from annealed bar and then hardened.
What surface finishes work on 6CrMnSi2Mo1V?
Protect against decarburization during heat treatment (vacuum, controlled atmosphere or pack); finish with grinding plus black oxide, phosphating, nitriding or PVD/TiN for wear and rust protection — no anodizing.
6CrMnSi2Mo1V 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 | 0.5 – 0.65 | 0.57 |
| Sihigh Si gives resistance to softening on tempering; increases decarburization tendency | 1.75 – 2.25 | 2 |
| Mn | 0.6 – 1 | 0.8 |
| Cr | 0.2 – 0.5 | 0.35 |
| MoChinese designation implies the upper (~1 %) Mo range | 0.2 – 1.35 | 0.9 |
| V | 0.15 – 0.35 | 0.25 |
| Pimpurity limit | ≤ 0.03 | — |
| Simpurity limit | ≤ 0.03 | — |
| Fe | balance | — |
6CrMnSi2Mo1V Q&T 57-59 HRC — frequently asked
What is 6CrMnSi2Mo1V Q&T 57-59 HRC used for?
6CrMnSi2Mo1V Q&T 57-59 HRC is typically used for punches, shear blades and pneumatic tools. In short: highest-toughness shock grade; air hardening, low distortion; machined then hardened.
What is the yield strength of 6CrMnSi2Mo1V Q&T 57-59 HRC?
6CrMnSi2Mo1V Q&T 57-59 HRC has a typical yield strength of 1,800 MPa (261 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 6CrMnSi2Mo1V Q&T 57-59 HRC easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of steel grades). Machine only in the annealed state (≈200 HB, ~55 % of AISI 1212) with rigid setups and sharp carbide/HSS tooling; after hardening only grinding and EDM are practical, and EDM'd surfaces should be stress-relieved.
Can 6CrMnSi2Mo1V Q&T 57-59 HRC be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — repair welding only with matching or low-hydrogen tool-steel filler, preheat 300–350 °C, keep interpass temperature, and temper immediately at the part's tempering temperature to avoid cracking.
What surface finishes work on 6CrMnSi2Mo1V Q&T 57-59 HRC?
Protect against decarburization during heat treatment (vacuum, controlled atmosphere or pack); finish with grinding plus black oxide, phosphating, nitriding or PVD/TiN for wear and rust protection — no anodizing.
Can 6CrMnSi2Mo1V Q&T 57-59 HRC be formed, bent or molded?
Hot forge 1050 → 900 °C with slow furnace cooling and mandatory anneal; cold forming is impractical, so shapes are machined from annealed bar and then hardened.
What is the maximum service temperature of 6CrMnSi2Mo1V Q&T 57-59 HRC?
6CrMnSi2Mo1V Q&T 57-59 HRC is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- GB/T 1299 (Alloy tool steels) (2014)
- ASTM A681 Standard Specification for Tool Steels Alloy — ASTM International (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating of Tool Steels — ASM International (1991)
- ASM Handbook Vol.16 — Machining (tool steel machinability ratings) — ASM International (1989)
- Shock-resisting tool steel (S5/S7 class) data sheets — Crucible / Böhler-Uddeholm (2020)
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.