A2 Tool Steel Bar Blanks

A2 tool steel bar blanks are the premier air-hardening cold work tool steel, delivering the best overall balance of wear resistance, toughness, and dimensional stability in heat treatment among the common tool steel grades. The nominal composition of 1.00% carbon, 5.25% chromium, 1.10% molybdenum, and 0.25% vanadium produces a deep-hardening steel that achieves full hardness by air cooling rather than oil or water quenching, resulting in minimal distortion and predictable size change. The air-hardening characteristic is A2's defining advantage for precision tooling. Because the steel does not require the rapid cooling of an oil or water quench, thermal gradients during hardening are greatly reduced. This translates to less warping, less cracking risk, and more consistent final dimensions compared to O1 or water-hardening grades. For complex die shapes, tight-tolerance gauges, and mold components where post-heat-treatment grinding must be minimized, A2 is the standard specification. Heat treatment for A2 involves austenitizing at 1,750-1,800°F with a 20-45 minute soak, followed by air cooling. As-quenched hardness reaches 62-64 HRC. Double tempering at 350-400°F yields 59-61 HRC for cold work tooling, while tempering at 950°F takes advantage of A2's secondary hardening peak for applications requiring hot work resistance. A2 offers better toughness than D2 at comparable hardness, making it the preferred choice for tooling subjected to impact loading such as blanking punches, cold heading dies, and shear blades. Our A2 bar blanks ship in the annealed condition, precision ground to standard flat bar and oversized block dimensions.