Tool Steel A2

AISI A2 represents the benchmark for versatility in the cold-work tool steel family. It is an air-hardening alloy that offers a superior compromise between the toughness of S7 and the wear resistance of D2. The defining characteristic of A2 is its excellent dimensional stability during heat treatment; because it is air-quenched rather than oil-quenched, internal stresses and warping are minimized. At Jucheng Precision, we leverage this stability to manufacture high-precision punch dies, intricate gauges, and robust machine components. We manage the entire process—from initial CNC milling in the annealed state to final precision grinding of the hardened (58-62 HRC) part—ensuring your tools deliver millions of cycles without failure.

Back to Materials Get a Quote
Tool Steel A2

Tool Steel A2 Machining Capabilities

Capability Technical Description Jucheng Advantage
Annealed State Milling A2 is typically machined in its annealed state (~200 HB). We utilize high-speed milling to create complex die geometries before hardening. Our 5-axis Haas machines can carve intricate pockets and profiles with high efficiency, reducing lead times for custom tooling.
Hard Milling (Post-Heat Treat) Finishing A2 after it has been air-hardened to 58-62 HRC using specialized ceramic or CBN cutting tools. Allows us to correct any micro-distortions from heat treat, ensuring that critical die features align perfectly without heavy grinding.
Precision Surface Grinding Achieving ultimate flatness and parallelism on A2 plates and blocks post-hardening. We hold flatness tolerances within 0.005mm, which is essential for multi-stage stamping dies and precision jigs.
Wire EDM Integration Using Wire EDM to cut sharp internal corners and complex profiles into hardened A2 blocks. Jucheng provides a complete workflow: CNC Roughing -> Heat Treat -> Wire EDM Finish -> Precision Grind.

Fabrication Guidelines for Tool Steel A2

Dimensional Stability:
A2 is an “Air-Hardening” steel, meaning it distorts significantly less during heat treatment than oil-hardened steels (like O1). Tip: This makes it ideal for complex dies where dimensional precision is critical.

Heat Treatment Process:
To achieve peak performance, A2 must be heated to ~950°C and then cooled in still air. Tip: We always perform double tempering to ensure the material is stabilized and reaches a consistent 58-62 HRC.

Corner Radii:
Even though A2 is stable, sharp internal corners can still act as stress risers. Tip: Always include a small radius (min 0.5mm) in milled pockets to improve the tool’s fatigue life.

Grinding Precautions:
Hardened A2 can be sensitive to “grinding burns” if the wheel is too aggressive. Tip: We use specific wheel grades and light passes to prevent surface softening during the finish grind.

Primary Applications

Stamping & Blanking Dies
Punches, die segments, and stripper plates for high-volume metal forming where wear resistance is paramount.

Precision Gauges
Ring gauges, plug gauges, and master blocks that must maintain their size over years of industrial use.

Industrial Knives
Shear blades, rotary cutters, and wood-chipping knives requiring a balance of toughness and edge retention.

Injection Mold Inserts
Small, high-wear inserts in plastic molds where A2 provides better durability than standard P20 or 420 stainless.

Properties

Density 7.86 g/cm³
Tensile Strength 2000+ MPa
Yield Strength 1500+ MPa
Hardness 58 - 62 HRC
Impact Strength 27 J (Charpy V-notch)
Thermal Conductivity 26.0 W/m-K
Machinability Rating 60% (Annealed)
Weldability Poor
Wear Resistance High
Stability in HT Superior
Max Part Size 2000 x 800 x 600 mm