Tool Steel A2 Square Bar 1/4" square Retail Price

About A2|Air-hardening tool steel. The general-purpose die steel. Hardens uniformly by cooling in still air after austenitizing, which minimizes distortion compared to oil- or water-hardening grades. Reaches HRC 57-62 with good toughness and wear resistance. Machine annealed (HRC ~25), then heat treat. In the annealed state it machines reasonably well with carbide. After hardening, it's grinding and EDM only. Used for blanking dies, forming dies, punches, and gauges. Compare to D2 (higher wear resistance, more chromium) and O1 (oil-hardening, cheaper, more distortion during heat treat).

About Square Bar|Solid square stock used for keys, keystock, spacers, and parts with flat reference surfaces. It's easier to clamp in a vise than round bar when you need to mill features on multiple sides.