C06_01_QQ-S-681b_Section_J_0004.pdf

This is a Federal Specification for Steel Castings (QQ-S-681b), dated November 6, 1941, with amendments through July 18, 1952, approved for use by all Federal departments and establishments.

The specification establishes requirements for eight classes of steel castings: Class X (common, no heat treatment or testing), Class O (common, annealed, no testing), Class 1 (soft, annealed, tested), Class 2 (medium, annealed, normalized, or normalized and tempered; tested), Class 3 (hard, annealed, tested), and Class 4 with subclasses (4A1, 4A2, 4B1, 4B2, 4B3, 4C1, 4C2, 4C3, 4C4) designed to meet specific physical properties. Steel castings must be made by electric furnace, converter, or open hearth processes and be of uniform quality, free from blowholes, porosity, hard spots, shrinkage defects, cracks, and other injurious defects. Chemical requirements specify maximum limits for carbon, manganese, phosphorus, sulfur, silicon, copper, and nickel depending on class. Physical properties including tensile strength, yield point, elongation, reduction of area, and cold bend capabilities vary by class and are detailed in Table I. Heat treatment requirements range from none for Classes X and O to annealing, normalizing, quenching, and tempering for Class 4 subclasses. The specification addresses cleaning, repair by welding (with carbon content restrictions for high-carbon castings), marking, packaging, inspection procedures, test specimen requirements, and Government chemical analysis. Navy Department purchases are made under Navy Specification 49S1 for administrative reasons.