Tool Steel O1 Square Bar 1/4" square Retail Price

About O1|Oil-hardening tool steel. The simplest and most forgiving tool steel to heat treat. Austenitize at 1450°F, quench in oil, temper. Reaches HRC 57-62. Lower cost than A2 or D2. The tradeoff is more distortion during heat treatment compared to air-hardening grades. Machines well annealed. Used for jigs, fixtures, gauges, blanking dies, and hand tools. Popular with hobbyists and bladesmiths because of the straightforward heat treatment. Compare to A2 (less distortion, more expensive) and W1 (water-hardening, even cheaper but even more distortion).

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.