American angles equivalent to GB/T 9787 (China's standard for hot-rolled equal and unequal leg angles) are regulated by three core ASTM standards, which align with GB standards in material, dimensional, and quality requirements:
1. ASTM A992/A992M-22 (Material Standard for High-Strength Angles)
This standard specifies material requirements for structural steels used in angles, channels, and beams-equivalent to GB/T 1591 (which governs Q355B). Key alignments with GB/T 1591 include:
Strength Requirements: Minimum yield strength of 50 ksi (345 MPa) for A992, matching Q355B's 345 MPa for sections >16 mm.
Chemical Limits: Identical caps for phosphorus (0.035%) and sulfur (0.035%), ensuring corrosion resistance and weldability.
Testing Protocols: Mandatory tensile, impact, and chemical analysis tests-same as GB/T 1591-with results documented in mill test reports (MTRs) for traceability.
2. ASTM A36/A36M-22 (Material Standard for General-Purpose Angles)
ASTM A36 is the equivalent of GB Q235B, governing general-purpose structural angles for light-load applications (e.g., residential framing, small machinery supports). Alignments with GB/T 700 (which governs Q235B) include:
Yield Strength: 36 ksi (248 MPa) for A36 vs. 235 MPa for Q235B-slightly higher, but compatible for light loads (e.g., a L2x2x0.25 A36 angle supports the same shelf load as a L50x50x5 Q235B angle).
Tensile Strength: 58–79 ksi (400–545 MPa) for A36 vs. 375–500 MPa for Q235B-overlapping for most light structural uses.
Elongation: 20% minimum for A36 (over 2 inches) vs. 26% for Q235B (over 50 mm)-both sufficient for bending and welding without cracking.