Steel A2
AISI/SAE A2 · UNS T30102 · EN 1.2363, X100CrMoV5 · JIS SKD12 · GB Cr5Mo1V
A2 (1.2363 / X100CrMoV5 / SKD12) is a 1 %C–5 %Cr–1 %Mo–V air-hardening cold-work tool steel that hardens to 57–62 HRC in air, giving very low distortion and good size stability compared with oil-hardening O1 or water-hardening W1.
Values for the Annealed condition
A2 tempers and conditions
A2 is supplied in 6 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft annealed bar, plate and precision-ground flat stock (≤235 HB) | Standard as-supplied condition for machining dies and punches before hardening; also the form of ground flat stock. | 470 | 740 | 22 | 217 HB | — |
Hardened & Tempered 54–56 HRC | Choose for heavy shear blades, cold forming and trimming tools where chipping is the failure mode. | 1,650 | 1,900 | 3 | 55 HRC | 2.6 % IACS |
Hardened & Tempered 57–59 HRC | Best general-purpose die hardness for medium-gauge blanking and forming with some impact loading. | 1,800 | 2,050 | 2 | 58 HRC | 2.5 % IACS |
air quench from 940–980 °C, temper 175–230 °C (58–62 HRC) | General working condition for blanking dies, punches and shear blades needing maximum wear resistance. | 1,900 | 2,150 | 1.5 | 60 HRC | — |
Hardened & Tempered 60–62 HRC | Pick for thin-sheet blanking punches and gauges where abrasive wear, not shock, governs life. | 1,950 | 2,250 | 1 | 61 HRC | 2.5 % IACS |
Hardened, deep-cryogenic treated (−185 °C) and double tempered, 59–62… | Used for precision gauges and long-run dies where retained austenite must be minimised for size stability and wear. | 1,950 | 2,200 | 1 | 61 HRC | 2.5 % IACS |
What is A2?
A2 (1.2363 / X100CrMoV5 / SKD12) is a 1 %C–5 %Cr–1 %Mo–V air-hardening cold-work tool steel that hardens to 57–62 HRC in air, giving very low distortion and good size stability compared with oil-hardening O1 or water-hardening W1. It is the standard choice for blanking and forming dies, punches, shear blades, gauges and precision-ground flat stock where dimensional accuracy after heat treatment matters. Wear resistance and compressive strength are far below the 12 %Cr D2 grade, corrosion resistance is only marginally better than plain carbon steel, and it is essentially non-weldable in the hardened state. A2 has a density of 7.86 g/cm³ (0.284 lb/in³), heavier than 90% of steel grades. It melts at 1,420°C (2,588 °F). A2 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 57% of steel grades. Elongation at break is 22% and the elastic modulus is 203 GPa (29.4 Msi).
What is A2 used for?
- Blanking dies
- Forming punches
- Shear and trim blades
- Cold-work die inserts
- Gauges and checking fixtures
- Precision-ground flat stock details
- Punches and stripper plates
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- 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 87% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
A2 properties
Typical room-temperature values for A2-Annealed; bars are the position among steel grades.
Physical3
A2 has a density of 7.86 g/cm³ (0.284 lb/in³), heavier than 90% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
A2 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 57% of steel grades. Elongation at break is 22% and the elastic modulus is 203 GPa (29.4 Msi).
Thermal6
A2 is rated for continuous service to 425°C (797 °F). It conducts heat at 26 W/m·K (15 BTU/hr·ft·°F), worse than 87% of steel grades. Thermal expansion is 10.7 µm/m·K (5.94 µin/in·°F).
Electrical3
A2 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 takes about 36 MJ of energy and emits 2.6 kg of CO₂ — more than 89% of steel grades. Typical recycled content is 35%.
Manufacturability8
A2's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (20/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. A2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A2
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.
Manufacturability
The process limits FabDigit's quote engine applies to A2. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Fair45 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
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 |
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.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel A2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T30102
- EN / DIN / Werkstoff-Nr.
- 1.2363X100CrMoV5X100CrMoV5-1
- GB (China)
- Cr5Mo1V
- JIS
- SKD12
How much does A2 cost?
A2 is a premium-cost steel ($$$), cheaper than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
A2 — frequently asked
What is A2 used for?
A2 is typically used for blanking dies, forming punches, shear and trim blades, cold-work die inserts, gauges and checking fixtures and precision-ground flat stock details. In short: versatile air-hardening tool.
What is the yield strength of A2?
A2 has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 57% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is A2 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed condition with carbide or cobalt HSS at moderate speeds; leave 0.2–0.5 mm grinding stock, stress-relieve rough-machined dies at 650–700 °C, and finish hardened parts by grinding, EDM or hard turning.
Can A2 be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — for repair only: preheat to 400–500 °C, use matched 5 %Cr filler, weld hot and temper immediately at the original tempering temperature to avoid cracking.
What surface finishes work on A2?
Takes a fine mirror polish when hardened; protect with oil, black oxide, or apply nitriding, hard chrome or TiN/CrN/TiCN PVD (below tempering temperature) to boost wear and galling resistance.
Can A2 be formed, bent or molded?
Cold forming is impractical; hot work at 900–1050 °C with slow cooling, then full anneal at 845–870 °C (furnace cool 10–20 °C/h) before machining. Hardening: austenitise 940–980 °C, air (or plate/vacuum) quench, temper twice.
What is the maximum service temperature of A2?
A2 is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does A2 cost?
A2 is a premium-cost steel ($$$), cheaper than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in A2?
Yes — A2 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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.