In modern US building construction, ASTM A992 has largely become the default material for rolled wide-flange shapes, superseding A36 for many applications. Here is a key comparison:
| Property / Standard | ASTM A36 H-Beam | ASTM A992 H-Beam |
|---|---|---|
| Minimum Yield Strength (Fy) | 36 ksi (250 MPa) | 50 ksi (345 MPa) |
| Maximum Yield Strength | Not specified. | 65 ksi (450 MPa) – A cap ensures consistency and prevents over-design. |
| Tensile to Yield Strength Ratio (Fu/Fy) | Not specified. | ≤ 0.85 – This mandatory ratio guarantees a minimum level of ductility and strain hardening. |
| Chemistry | More flexible ranges. | Tighter controls, particularly on carbon, manganese, and phosphorous. |
| Primary Advantage | General purpose, cost-effective, excellent weldability. | Higher strength allows for smaller, lighter sections. More consistent, predictable properties enhance design efficiency and safety. |
While A36 is still used and valid, A992 offers structural and economic advantages for primary framing, leading to its prevalence in new building design per the AISC Specification.