Steel A2 · hardness band
Steel A2 HT 54-56 HRC
Properties of the HT 54-56 HRC condition, compared with the other A2 tempers.
Choose for heavy shear blades, cold forming and trimming tools where chipping is the failure mode.
What is A2 HT 54-56 HRC?
A2 HT 54-56 HRC is A2 heat treated to HT 54-56 HRC — choose for heavy shear blades, cold forming and trimming tools where chipping is the failure mode. A2 HT 54-56 HRC has a yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,900 MPa (276 ksi) — stronger than 99% of steel grades. Elongation at break is 3% and the elastic modulus is 203 GPa (29.4 Msi). A2 HT 54-56 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; HT 54-56 HRC is available on request or by drawing note.
Advantages
- High strength — 1,650 MPa (239 ksi), better than 99% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Limited ductility — 3%, worse than 99% of steel grades
- Low electrical conductivity — 2.7 % IACS, worse than 96% of steel grades
- Poor heat conductor — 26 W/m·K (15 BTU/hr·ft·°F), worse than 86% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 86% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
A2 HT 54-56 HRC properties
Typical room-temperature values for A2 HT 54-56 HRC — 9 properties are specific to this condition; the rest are grade-level values shared by every A2 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
A2 HT 54-56 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
A2 HT 54-56 HRC has a yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,900 MPa (276 ksi) — stronger than 99% of steel grades. Elongation at break is 3% and the elastic modulus is 203 GPa (29.4 Msi).
Thermal6
A2 HT 54-56 HRC is rated for continuous service to 400°C (752 °F). It conducts heat at 26 W/m·K (15 BTU/hr·ft·°F), worse than 86% of steel grades. Thermal expansion is 10.7 µm/m·K (5.94 µin/in·°F).
Electrical3
A2 HT 54-56 HRC conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (20/100), better than 87% of steel grades.
Sustainability4
Producing a kilogram of A2 HT 54-56 HRC takes about 36 MJ of energy and emits 2.6 kg of CO₂ — more than 88% of steel grades. Typical recycled content is 35%.
Manufacturability8
A2 HT 54-56 HRC's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (20/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other A2 tempers and conditions
A2 is also supplied in 6 other conditions. The full side-by-side table is on the A2 overview.
- AnnealedDefaultStandard as-supplied condition for machining dies and punches before hardening; also the form of ground flat stock.470 MPa yield · 217 HB
- Hardened & TemperedGeneral working condition for blanking dies, punches and shear blades needing maximum wear resistance.1,900 MPa yield · 60 HRC
- Q&TOrder this when the supplier heat treats to a customer-specified hardness band rather than the maximum.1,800 MPa yield · 58 HRC
- HT 54-56 HRCChoose for heavy shear blades, cold forming and trimming tools where chipping is the failure mode.1,650 MPa yield · 55 HRC
Working with A2 HT 54-56 HRC
Is A2 easy to machine?
Machine in the annealed condition with carbide or cobalt HSS at moderate speeds; leave 0.2–0.5 mm grinding stock, stress-relieve rough-machined dies at 650–700 °C, and finish hardened parts by grinding, EDM or hard turning.
Can A2 be welded?
Poor weldability — for repair only: preheat to 400–500 °C, use matched 5 %Cr filler, weld hot and temper immediately at the original tempering temperature to avoid cracking.
Can A2 be formed, bent or molded?
Cold forming is impractical; hot work at 900–1050 °C with slow cooling, then full anneal at 845–870 °C (furnace cool 10–20 °C/h) before machining. Hardening: austenitise 940–980 °C, air (or plate/vacuum) quench, temper twice.
What surface finishes work on A2?
Takes a fine mirror polish when hardened; protect with oil, black oxide, or apply nitriding, hard chrome or TiN/CrN/TiCN PVD (below tempering temperature) to boost wear and galling resistance.
A2 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 A2 | 0.95 – 1.05 | 1 |
| Mn | 0.4 – 1 | 0.7 |
| Si | 0.1 – 0.5 | 0.3 |
| Cr | 4.75 – 5.5 | 5.1 |
| Mo | 0.9 – 1.4 | 1.1 |
| V | 0.15 – 0.5 | 0.25 |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.25 | — |
| Wresidual | ≤ 0.3 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
A2 HT 54-56 HRC — frequently asked
What is A2 HT 54-56 HRC used for?
A2 HT 54-56 HRC is typically used for blanking dies, forming punches, shear and trim blades, cold-work die inserts, gauges and checking fixtures and precision-ground flat stock details. In short: versatile air-hardening tool.
What is the yield strength of A2 HT 54-56 HRC?
A2 HT 54-56 HRC has a typical yield strength of 1,650 MPa (239 ksi) and a tensile strength of 1,900 MPa (276 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is A2 HT 54-56 HRC easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed condition with carbide or cobalt HSS at moderate speeds; leave 0.2–0.5 mm grinding stock, stress-relieve rough-machined dies at 650–700 °C, and finish hardened parts by grinding, EDM or hard turning.
Can A2 HT 54-56 HRC be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — for repair only: preheat to 400–500 °C, use matched 5 %Cr filler, weld hot and temper immediately at the original tempering temperature to avoid cracking.
What surface finishes work on A2 HT 54-56 HRC?
Takes a fine mirror polish when hardened; protect with oil, black oxide, or apply nitriding, hard chrome or TiN/CrN/TiCN PVD (below tempering temperature) to boost wear and galling resistance.
Can A2 HT 54-56 HRC be formed, bent or molded?
Cold forming is impractical; hot work at 900–1050 °C with slow cooling, then full anneal at 845–870 °C (furnace cool 10–20 °C/h) before machining. Hardening: austenitise 940–980 °C, air (or plate/vacuum) quench, temper twice.
What is the maximum service temperature of A2 HT 54-56 HRC?
A2 HT 54-56 HRC is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in A2 HT 54-56 HRC?
Yes — A2 HT 54-56 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 — Alloy Tool Steels — ASTM International (2015)
- DIN EN ISO 4957 — Tool steels (X100CrMoV5, 1.2363) — DIN/ISO (2018)
- JIS G4404 — Alloy tool steels (SKD12) — JSA (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Tool Steels, 5th ed. — ASM International (1998)
- Cold work tool steel 1.2363 / A2 datasheet — Böhler / voestalpine (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.