Crucible Steel AIRKOOL® (AISI A2) Tool Steel

Crucible Steel AIRKOOL® (AISI A2) Tool Steel Product Information -:- For detailed product information, please contact sales. -: Crucible Steel AIRKOOL® (AISI A2) Tool Steel Synonyms -:- For detailed product information, please contact sales. -:

Crucible Steel AIRKOOL® (AISI A2) Tool Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: Crucible AIRKOOL® (AISI A2) Tool Steel** Crucible AIRKOOL® is a premium, medium-alloy, air-hardening cold work tool steel that conforms to the widely adopted AISI A2 specification. Renowned for its **excellent balance of wear resistance, toughness, and dimensional stability**, AIRKOOL® embodies the ideal properties for a versatile tool steel capable of handling a broad range of demanding applications. Its name directly reflects its primary advantage: **excellent air-hardening characteristics ("AIR") coupled with good resistance to softening during use ("KOOL")**, minimizing distortion and quench-cracking risks associated with oil-hardening grades. Formulated with a balanced chromium-carbon-molybdenum composition, AIRKOOL® provides superior performance compared to oil-hardening O-series steels (like O1) in terms of wear life and stability, while offering better toughness and machinability than higher-alloy, higher-wear steels like D2. It is the quintessential "all-rounder" tool steel, trusted for precision tooling that requires a reliable combination of durability, stability, and ease of heat treatment. --- ## **1. Chemical Composition (Weight %)** The composition adheres to the AISI A2 standard, optimized for air hardenability and a balanced carbide structure. | **Element** | **Carbon (C)** | **Chromium (Cr)** | **Molybdenum (Mo)** | **Vanadium (V)** | **Manganese (Mn)** | **Silicon (Si)** | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **Content** | 0.95 - 1.05 | 4.75 - 5.50 | 0.90 - 1.10 | 0.15 - 0.30 | 0.40 - 0.70 | 0.15 - 0.30 | | **Role** | Provides base hardness and forms chromium carbides for wear resistance. Level is optimized for toughness-wear balance. | Primary alloy for deep air hardenability. Forms hard (Cr₇C₃) carbides, contributing significantly to wear resistance. | Enhances hardenability, refines grain structure, improves toughness, and increases resistance to tempering. | Refines grain size, improves toughness and wear resistance by forming fine, hard vanadium carbides. | Aids in deoxidation and contributes to hardenability. | Acts as a deoxidizer during steelmaking; provides some solid solution strengthening. | *Note: Iron (Fe) constitutes the remainder. The resulting carbide volume (~5-7%) is lower than D2, contributing to better toughness.* --- ## **2. Physical & Mechanical Properties** *Typical properties after proper heat treatment to 58-62 HRC.* * **Density:** ~7.86 g/cm³ (0.284 lb/in³) * **Modulus of Elasticity:** ~210 GPa (30.5 x 10⁶ psi) * **Thermal Conductivity:** Approximately 26 W/m·K at 20°C. * **Coefficient of Thermal Expansion:** ~11.5 x 10⁻⁶/°C (20-200°C) * **Hardenability:** **Excellent.** Deep air-hardening characteristics; can fully harden in substantial cross-sections with minimal distortion. * **Hardness (Typical Working Range):** **57 - 62 HRC.** Most commonly and optimally used at **59-61 HRC**. * **Wear Resistance:** **Good to Very Good.** Superior to oil-hardening grades (O1) due to higher alloy content and carbide volume, but less than high-chromium steels like D2. Excellent for many stamping and forming applications. * **Toughness:** **Very Good.** A key strength of A2. It offers significantly higher impact toughness than D2, making it more resistant to chipping and cracking in applications with moderate shock or intermittent loading. * **Dimensional Stability:** **Excellent.** Air hardening results in minimal size change and distortion, making it ideal for precision tools, gauges, and complex shapes. * **Machinability (Annealed):** **Good.** Better than higher-alloy tool steels like D2, reducing manufacturing time and cost. --- ## **3. Heat Treatment** * **Annealing:** Heat to 845-870°C (1555-1600°F), slow cool in furnace at ≤15°C/hr to 600°C, then air cool. Annealed hardness: 200-235 HB. * **Stress Relieving:** 650-675°C (1200-1250°F), hold, then slow cool. * **Preheating:** **Highly Recommended.** Preheat at 730-790°C (1350-1450°F) to minimize thermal shock and distortion. * **Austenitizing:** **925-980°C (1700-1795°F).** A common and effective temperature is **955-970°C (1750-1780°F)**. * **Quenching:** **Air quench** in still or forced air. For optimal dimensional stability on complex parts, a interrupted air quench to ~540°C (1000°F) followed by still air cooling is highly effective. **Do not oil quench.** * **Tempering:** **Mandatory.** Temper immediately after quenching. **Two tempers**, each for 2+ hours, are recommended for stability. * **Typical Tempering Range:** **205-540°C (400-1000°F).** * For a hardness of 59-61 HRC: Temper at **425-540°C (800-1000°F)**. * **Avoid prolonged tempering in the 260-375°C (500-700°F) range** due to potential temper embrittlement. --- ## **4. Key Applications** AIRKOOL® (A2) is an extremely versatile steel used across countless precision tooling applications. * **Precision Blanking & Forming Dies:** Punches, dies, and stripper plates for medium to long-run stamping of metals. * **Master Hubs, Form Rolls, & Mandrels:** Tools for cold forming shapes, threads (roll forming), and tubing. * **Gages & Measuring Tools:** Thread plugs, ring gages, and fixtures requiring dimensional stability and wear resistance. * **Shear & Slitter Knives:** Blades for cutting metal, paper, and plastics. * **Industrial Knives & Cutting Tools:** Woodworking knives, plastic granulator blades, and cutting inserts. * **Molds & Tooling for Plastics & Rubber:** Cavities, cores, and ejector pins requiring polishability and wear resistance. * **Machine Components:** Cams, wear plates, and guides. --- ## **5. International Standards & Cross-References** Crucible AIRKOOL® is the brand name for Crucible's AISI A2 grade. * **AISI/SAE:** **A2** * **UNS:** T30102 * **European (EN):** **1.2363** (X100CrMoV5-1-1) * **Japanese (JIS):** **SKD12** * **ISO:** HS 6-5-2 (approximate classification) * **Common Trade Names:** A2 Tool Steel, Air-Hardening A2. --- ## **6. Advantages & Limitations** **Advantages:** * **Superb Balance of Toughness & Wear Resistance:** Its most celebrated attribute, making it a reliable, general-purpose choice. * **Exceptional Dimensional Stability:** Minimal distortion simplifies the manufacture of complex, precision tools. * **Good Machinability & Grindability:** Easier and more cost-effective to machine and finish than many other tool steels. * **Deep, Reliable Air Hardenability:** Simplifies heat treatment and reduces risk of quench cracks. * **Proven Versatility:** A trusted, well-understood material suitable for a vast array of tooling challenges. **Limitations:** * **Not Stainless:** Will corrode if not protected; corrosion resistance is only slightly better than carbon steels. * **Lower Wear Resistance than D2/High-Alloy Steels:** Not the best choice for extremely abrasive, high-volume applications. * **Limited Hot Hardness:** Not designed for high-temperature service; begins to soften significantly above ~425°C (800°F). --- ## **7. Summary** **Crucible AIRKOOL® (AISI A2) is the definitive balanced-performance, air-hardening tool steel, offering an unmatched combination of practicality, reliability, and versatility.** For tool designers and manufacturers who need a material that performs predictably across a wide spectrum of cold work applications—from precision gauges to robust forming dies—AIRKOOL® provides an optimal solution. It mitigates the risks of distortion and cracking while delivering a long service life through its excellent blend of wear resistance and toughness, solidifying its status as an industry staple for high-quality tooling. -:- For detailed product information, please contact sales. -: Crucible Steel AIRKOOL® (AISI A2) Tool Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6964 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Crucible Steel AIRKOOL® (AISI A2) Tool Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Crucible Steel AIRKOOL® (AISI A2) Tool Steel -:- For detailed product information, please contact sales. -: Chemical Identifiers Crucible Steel AIRKOOL® (AISI A2) Tool Steel -:- For detailed product information, please contact sales. -:

Packing of Crucible Steel AIRKOOL® (AISI A2) Tool Steel -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3435 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition