A2 steel – Steel for tools, dies and blades
A2 steel is one of the most available and widely used types of tool steel. It has deep hardening, low distortion and high safety in heat treatment, high resistance to softening at high temperatures and medium resistance to decarburization. It tends to retain austenite. During tempering and double tempering, austenite is generally eliminated or reduced to a negligible amount.
Properties of AISI type A2 tool steel
The properties of AISI type A2 tool steel are given in the tables below, including chemical composition, physical composition and hardness, etc.
Chemical composition
The following table lists the chemical composition of A2 steel.
| Composition of A2 Steel, % | |||||||||
| Standard | AISI | W | Yes | Mn | P, ≤ | S, ≤ | Cr | Mo | V |
| ASTM A681 | A2 | 0.95-1.05 | 0.10-0.50 | 0.40-1.00 | 0.030 | 0.030 | 4.75-5.50 | 0.90-1.40 | 0.15-0.50 |
Physical properties of material A2
The following tables show the physical properties of AISI A2 material, including density, melting point, specific heat, modulus of elasticity (modulus of elasticity), thermal conductivity and coefficient of thermal expansion (CTE), etc.
Grades:
- 10 -6 ·K -1 = 10 -6 /K
- 1Ω mm²/m = 1 μΩ m
- 1 g/cm3 = 1 kg/dm3 = 1000 kg/m3
- 1 GPa = 1kN/mm2
- 1 MPa = 1 N/mm2
| A2 Seel Physical Properties | Metric/SI | Imperial |
| Density | 7.86g/cm3 | 0.284 lb/in3 |
| Fusion point | 1425°C | 2,600°F |
| Specific thermal capacity | 460 J/kg·K at 20 °C | 0.11 Btu/lb°F at 68°F |
| Elastic modulus (Modulus of elasticity) | 190 Gpa at 20°C | 27.5×10 3 ksi at 68°F |
| 185 GPa at 190°C | 26.9 x 10 3 ksi at 375°F | |
| 180 GPa at 400°C | 24.6×10 3 ksi at 750°F | |
| Thermal conductivity | 26.0 W/m·K at 20 °C | 15.03 Btu/ft·h·°F at 68°F |
| 27.0 W/m·K at 190 °C | 15.61 Btu/ft·h·°F at 375°F | |
| 28.5 W/m·K at 400 °C | 16.5 Btu/ft·h·°F at 750°F | |
| Coefficient of thermal expansion (CTE) | 10.7 μm/m at 20-100 °C | 5.96 μin./in.°F at 70-200°F |
| 10.6 μm/m at 20-260 °C | 5.9 μin./in.·°F at 70-500 °F | |
| 12.9 μm/m at 20-425 °C | 7.2 μin./in.·°F at 70-800 °F | |
| 14.0 μm/m at 20-540 °C | 7.8 μin./in.·°F at 70-1000 °F | |
| 14.2 μm/m at 20-650 °C | 7.9 μin./in.·°F at 70-1200 °F |
Mechanical properties
The table below lists the mechanical properties of A2 tool steel, including tensile strength, yield strength, elongation, area reduction, etc.
| Quenching temperature, °C (°F), Hardened from 945°C (1730°F) |
Hardness, HRC | Ultimate tensile strength, MPa (ksi) | Yield strength, MPa (ksi) | Elongation by 50 mm, (2 in.), % | Area reduction, % |
| 540 (1000) | 54.1 | 1858.2 (269.5) | – | – | – |
| 595 (1100) | 46.7 | 1603.8 (232.6) | 1269 (184) | 5.0 | 13.9 |
A2 tool steel heat treatment
The following heat treatment of A2 tool steel, including normalizing and annealing, hardening and tempering, etc.
Annealing heat treatment
A2 steel annealing heat treatment temperature: 845-870°C (1550-1600°F), cooling rate: ≤22°C/h (40°F/h) to 705°C (1300°F), Brinell hardness is 201-229 HB. (Note: The upper limit of the range should be applied to the large section, while the lower limit to the smaller section. The time to maintain temperature varies from 1 hour for light steel to 4 hours for heavy steel and high-alloy steel. oven.)
Hardening and tempering of A2 tool steel
Preheating temperature: 788°C (1450°F), austenitizing temperature: 925-980°C (1700-1800°F), minimum austenitizing retention time: 20-45 minutes (for oven heat treatment. For package hardening, hold for 30 min/in package cross-section); Quenching medium: Air or nitrogen gas; Tempered hardness: 62-65 HRC (varies with austenitizing temperature);
Quenching temperature: 175-540°C (350-1000°F).
Stress relief
Recommended strain relief temperature: 650-675°C (1200-1250°F)
Forms
- Precision stamping dies,
- Erasure die,
- Die for cold forging, deep drawing and thread rolling,
- High speed suppression punch,
- stainless steel plate punch,
- Dying to draw,
- Crimping die,
- Die recording,
- Abrasive plastic mold die,
- Dies for line lamination,
- Cutting tools,
- meters,
- Blades and knives,
- Punching and cutting tools for medium thickness materials and sockets, etc.
AISI A2 steel equivalent material
Materials equivalent to AISI A2 steel are listed in the following table, including European EN (German DIN, British BSI, French NF…), ISO, Japanese JIS and Chinese GB standard (for reference).
| Material equivalent to A2 steel | |||||||||||||||||
| USA | ISO | European Union | Japan | China | Australia | India | Russia | Korea | |||||||||
| Standard | AISI (UNS) | Standard | Steel Number (Designation) | Standard | Steel Number (Designation) | Standard | Steel | Standard | Name | Standard | Note | Standard | Note | Standard | Note | Standard | Note |
| AISI, ASTM A681 |
A2 (T30102) | ISO 4957 | 1.2363 (X100CrMoV5) | EN ISO 4957 | 1.2363 (X100CrMoV5) | JIS G4404 | SKD12 | GB/T 1299 | Cr15Mo1V | ||||||||
Related Material: D2 Steel, SKD11 Steel, 1.2343 (X37CrMoV5-1)
