Steel A3 · hardness band
Steel A3 Q&T 56-58 HRC
Properties of the Q&T 56-58 HRC condition, compared with the other A3 tempers.
Pick when impact and chipping resistance matter more than maximum wear life.
What is A3 Q&T 56-58 HRC?
A3 Q&T 56-58 HRC is A3 heat treated to Q&T 56-58 HRC — pick when impact and chipping resistance matter more than maximum wear life. A3 Q&T 56-58 HRC has a yield strength of 1,700 MPa (247 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 99% of steel grades. Elongation at break is 3% and the elastic modulus is 203 GPa (29.4 Msi). A3 Q&T 56-58 HRC has a density of 7.86 g/cm³ (0.284 lb/in³), heavier than 89% 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
- High strength — 1,700 MPa (247 ksi), better than 99% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Difficult to machine — 8/100, worse than 100% of steel grades
- Limited ductility — 3%, worse than 99% 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
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
A3 Q&T 56-58 HRC properties
Typical room-temperature values for A3 Q&T 56-58 HRC — 13 properties are specific to this condition; the rest are grade-level values shared by every A3 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
A3 Q&T 56-58 HRC has a density of 7.86 g/cm³ (0.284 lb/in³), heavier than 89% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
A3 Q&T 56-58 HRC has a yield strength of 1,700 MPa (247 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 99% of steel grades. Elongation at break is 3% and the elastic modulus is 203 GPa (29.4 Msi).
Thermal6
A3 Q&T 56-58 HRC is rated for continuous service to 350°C (662 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 10.7 µm/m·K (5.94 µin/in·°F).
Electrical3
A3 Q&T 56-58 HRC conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of A3 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 30%.
Manufacturability8
A3 Q&T 56-58 HRC's machinability is not recommended (8/100, worse than 100% of steel grades); weldability poor (15/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other A3 tempers and conditions
A3 is also supplied in 5 other conditions. The full side-by-side table is on the A3 overview.
- AnnealedDefaultStandard stock condition for machining the tool before hardening.430 MPa yield · 19 HRC
- Q&T 60-62 HRCHighest practical wear resistance for A3 — for abrasive blanking, trim edges and gauges with rigid support.2,000 MPa yield · 61 HRC
- Q&T 58-60 HRCGeneral-purpose working hardness for blanking and forming dies — balanced wear and toughness.1,850 MPa yield · 59 HRC
- Q&T 56-58 HRCPick when impact and chipping resistance matter more than maximum wear life.1,700 MPa yield · 57 HRC
Working with A3 Q&T 56-58 HRC
Is A3 easy to machine?
Machine in the annealed condition with rigid setups, sharp carbide or cobalt HSS tooling and moderate speeds; the high vanadium carbide content accelerates tool and wheel wear, so allow generous grinding stock and finish by grinding after hardening.
Can A3 be welded?
Poor weldability — repair welding only, with 300–450 °C preheat, matching or Cr-Mo tool-steel filler, minimal heat input and an immediate temper at the previous tempering temperature.
Can A3 be formed, bent or molded?
Cold forming is impractical; hot work at 900–1050 °C with slow controlled cooling and full anneal (~845–870 °C, slow cool) afterwards; austenitize 940–970 °C, air quench, temper 175–540 °C — dimensional change on hardening is very small.
What surface finishes work on A3?
Not corrosion resistant: protect with oil, black oxide, phosphating, nitriding or PVD TiN/CrN; polishing is possible but coarse vanadium carbides limit true mirror finish.
A3 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 |
|---|---|---|
| CASTM A681 grade A3 | 1.2 – 1.3 | 1.25 |
| Mn | 0.4 – 0.6 | 0.5 |
| Si | ≤ 0.5 | 0.3 |
| Cr | 4.75 – 5.5 | 5.1 |
| Mo | 0.9 – 1.4 | 1.1 |
| Vhigh V gives extra wear resistance vs A2 | 0.8 – 1.4 | 1 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
A3 Q&T 56-58 HRC — frequently asked
What is A3 Q&T 56-58 HRC used for?
A3 Q&T 56-58 HRC is typically used for blanking and piercing dies, forming and coining punches, trim dies and die inserts, shear and slitter blades, thread-rolling dies and cold-forming tooling. In short: air-hardening cold-work tool.
What is the yield strength of A3 Q&T 56-58 HRC?
A3 Q&T 56-58 HRC has a typical yield strength of 1,700 MPa (247 ksi) and a tensile strength of 1,950 MPa (283 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is A3 Q&T 56-58 HRC easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of steel grades). Machine in the annealed condition with rigid setups, sharp carbide or cobalt HSS tooling and moderate speeds; the high vanadium carbide content accelerates tool and wheel wear, so allow generous grinding stock and finish by grinding after hardening.
Can A3 Q&T 56-58 HRC be welded?
Not readily — weldability is rated poor (15/100). Poor weldability — repair welding only, with 300–450 °C preheat, matching or Cr-Mo tool-steel filler, minimal heat input and an immediate temper at the previous tempering temperature.
What surface finishes work on A3 Q&T 56-58 HRC?
Not corrosion resistant: protect with oil, black oxide, phosphating, nitriding or PVD TiN/CrN; polishing is possible but coarse vanadium carbides limit true mirror finish.
Can A3 Q&T 56-58 HRC be formed, bent or molded?
Cold forming is impractical; hot work at 900–1050 °C with slow controlled cooling and full anneal (~845–870 °C, slow cool) afterwards; austenitize 940–970 °C, air quench, temper 175–540 °C — dimensional change on hardening is very small.
What is the maximum service temperature of A3 Q&T 56-58 HRC?
A3 Q&T 56-58 HRC is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in A3 Q&T 56-58 HRC?
Yes — A3 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
- ASTM A681 — Standard Specification for Tool Steels Alloy — ASTM International (2022)
- SAE J437/J438 — Tool and Die Steels — SAE International (2015)
- ASM Handbook Vol.1: Properties and Selection: Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- ASM Specialty Handbook: Tool Materials — ASM International (1995)
- ASM Handbook Vol.16: Machining — ASM International (1989)
- Air-hardening cold work tool steel (A2/A3 class) datasheets — Böhler / Crucible Industries (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.