The primary Chinese standard for angle steel is GB/T 706-2016 "Hot-rolled equal and unequal angle steel".
It specifies technical requirements for dimensions, shape, weight tolerance (±3% for weight per meter), chemical composition (e.g., C≤0.22% for Q235B, P/S≤0.035% max), and mechanical properties (tensile strength 375-500MPa for Q235B, elongation ≥26%). The standard also covers inspection methods: dimensional checks (using calipers for side length/thickness), mechanical testing (tensile and bending tests), and surface quality inspection (no cracks, folds, or severe rust). Delivery conditions are typically "hot-rolled, as-delivered," but normalized delivery is available for grades requiring improved toughness (e.g., Q355ND for low-temperature use).