Shipping Status: Pre-hardened to 980-1080N/mm2 (30-34HRC) Steel properties: The steel for the P20 plus 1.1% nickel, steel surface to the center of uniform hardness, good cutting, sparks and polishing excellent performance, suitable for gasification, Hard chrome plated and coated. Uses: Suitable for demanding plastic mold, especially the more than 400MM thick mold. :720-740 ℃ annealing heat through insulation sufficient time, and then the furnace cooled to 600 ℃, and then cooled in the air, from hardness of about 240HB (highest). Stress relief: heated to 600 ℃ in the protective gas furnace heat about 2 hours, and then slowly cooled with the furnace. :840-860 ℃ thermal quenching after quenching oil, or 860-880 ℃ heat immediately after the temperature cooled slightly higher than the tempering, the hardness from approximately 54HRC. Tempering: Temper immediately after quenching, the time of not less than 2-2.5 hours, then cooled baked. Dimensions: round (MM) 40.8 45.8 50.8 25.8 55.8 30.8 60.8 32.8 66.0 71.0 76.0 81.0 86.0 91.0 101.5 106.5 116.5 126.5 141.5 151.5 182.0 202.0 232.0 262.5 282.5 302.5 363.0 403.0 Square (MM) 25323540455060708090105