A2 Tool Steel Properties

A2 tool steel is a versatile and widely utilized material in the cold-work tooling sector. At Aobo Steel, we believe that selecting the right material is critical for your operational success. This guide details the essential A2 tool steel properties to help you determine if A2 is the optimal choice for your needs. A free download of the D2 tool steel properties PDF is available at the bottom of the page.

The Foundational Composition of A2 Tool Steel

The distinct A2 tool steel properties originate from its chemical composition. As an air-hardening, medium-alloy tool steel, A2’s ‘A’ designation signifies its air-hardening capability, achieved through high carbon and moderate alloy content. These alloys form hard carbide particles, enhancing wear resistance compared to lower-alloy steels.

While slight variations exist between specific melts, a typical chemical makeup for A2 tool steel includes:

Element	Approximate Content (%)	General Contribution to Properties
Carbon (C)	1.00	Hardness, wear resistance
Chromium (Cr)	5.25	Deoxidation strengthens steel
Molybdenum (Mo)	1.10 – 1.15	Hardenability, toughness, hot strength, wear resistance
Vanadium (V)	0.25 – 0.90	Wear resistance (carbide former), grain refinement
Manganese (Mn)	0.60 – 0.70	Hardenability, deoxidation
Silicon (Si)	0.30	Deoxidation, strengthens steel

Understanding this composition is key to appreciating the full range of A2 tool steel properties.

Key A2 Tool Steel Properties for Your Factory

A2 tool steel offers a balance of characteristics suitable for numerous applications. Here are the specific A2 tool steel properties relevant to end-users:

Hardness and Tempering Resistance

A primary aspect of A2 tool steel properties is its achievable hardness. A2 is typically heat-treated to a working hardness of 58–60 HRC, with some references suggesting up to 64 HRC.

After austenitizing at around 968°C (1775°F) and air cooling, A2 achieves maximum as-quenched hardness due to almost complete martensitic transformation. It exhibits better tempering resistance than plain carbon or O2 tool steels, and a minor secondary hardening peak can develop when tempered at approximately 510°C (950°F). More information about heat treatment, please click A2 steel heat treatment guide.

Wear Resistance

A2 tool steel possesses high abrasion resistance, rated as “Very Good.”

• It offers slightly better wear resistance than water-hardening steels with similar carbon content.
• It provides more abrasion resistance than S-series shock-resistant steels.
• In terms of wear resistance, A2 is positioned between O1 (lower) and D2 (higher) tool steels.

For more information, please click A2 tool steel wear resistance.

Toughness

Good toughness is another important characteristic among A2 tool steel properties. It is generally considered to have higher toughness than oil-hardening die steels like O1 tool steel and exhibits better toughness and ductility than D-series high-wear steels. A2 is rated as “Good” for toughness.

Dimensional Stability

One of the significant A2 tool steel properties is its minimal movement in hardening (low distortion). When air quenched from the proper hardening temperature (around 968°C or 1775°F), A2 is expected to expand approximately 0.001 in./in. (0.001 mm/mm). Part geometry can, however, introduce variations.

Machinability

A2 is considered a relatively easy machining tool steel. Its machinability rating is around 60-65% in its properly annealed state compared to a 1% carbon tool steel (W1) rated at 100%. It’s rated as “Good” for machinability, especially compared to D2 tool steel, which has poor machinability.

Hot Hardness

While A2 demonstrates good temper resistance and secondary hardening, its hot hardness is not sufficient for high-speed machining or hot-work applications. It is typically used at low temperatures, usually room temperature, due to a low potential for hardness retention at hot conditions. For more information, please click A2 tool steel hardness.

Safety in Hardening

A2 is known for its safety in hardening. Air quenching helps minimize distortion and promotes good dimensional stability during heat treatment.

Applications

The balanced A2 tool steel properties make it a versatile choice for a wide spectrum of tooling. It is often used for:

• Bending dies
• Blanking dies and punches, particularly for long runs
• Mandrels used in spinning operations
• Tools for blanking sizable production lots of hot-rolled unpickled steel (due to its high abrasion resistance)
• Plastics molding tooling

A2 is frequently selected when an application is less demanding in wear than D2 might cater to, but requires higher toughness.

A2 Tool Steel Properties: Comparative Insights

Comparing A2 tool steel properties with other grades is essential for selection:

• A2 vs. O1: O1 is a low-cost alternative with high hardness and wear resistance, but it offers lower toughness than A2. If O1 presents hardenability issues for an application, A2 can be a suitable replacement due to its better dimensional stability and air-hardening nature.
• A2 vs. D2: D2 tool steel has excellent wear resistance and nondeforming properties. However, A2 is often chosen when the application requires higher toughness and better machinability than D2, even with slightly less wear resistance.

Partner with Aobo Steel for Your A2 Tool Steel Requirements

At Aobo Steel, we leverage over 20 years of experience in forging and supplying high-quality tool steels, including A2. Our understanding of A2 tool steel properties ensures you receive material meeting your specifications. With our network of over 40 stable suppliers, we provide reliable steel solutions.

Our team is ready to provide direct, knowledgeable advice if you are considering A2 tool steel or need assistance.

Conclusion: The Value of A2 Tool Steel

In summary, A2 is a robust, air-hardening tool steel offering a good balance of wear resistance, toughness, and dimensional stability in heat treatment. Its reasonable machinability makes it a versatile choice for many cold-working applications. Understanding these A2 tool steel properties is key to leveraging its benefits effectively.