A2 tool steel can be heat-treated to increase hardness and durability. Markforged recommends heat-treating A2 tool steel to optimize material properties, though it can be used as-sintered. Heat A2 Tool Steel part in a standard (non-vacuum) furnace to 970°C (1780°F) . Hold part at temperature for 30-45 minutes. Air quench part to below 65°C (150 °F). Double temper A2 Tool Steel part in a standard furnace. For each temper, heat part to 150-550°C (302-1022°F) and temper for 2 hours, or 1 hour per inch of thickness. Let part cool to room temperature between tempers.