ASTM A588 — Yield Strength, Tensile Strength and Applications
Weathering High-Strength Low-Alloy (HSLA) steel for shapes and plates. Forms a stable rust patina and serves unpainted in suitable atmospheres. Fy 50 ksi to 4 in. thick.
Strength
| Grade | Fy (ksi) | Fu (ksi) | Note |
|---|---|---|---|
| — (≤ 4 in.) | 50 | 70 | Full strength to 4 in. thick. |
| — (4–5 in.) | 46 | 67 | Reduced for 4 to 5 in. |
| — (5–8 in.) | 42 | 63 | Reduced for 5 to 8 in. |
Fy and Fu are specification minimums. Verify the grade on the Mill Test Report (MTR); dual-certified material is common.
Applicable members
W, M, S, HP, C, MC, L, WT, plates
Applicable is not the same as stocked. Confirm availability with the supplier.
Common applications
Exposed bridges, architectural exposed steel, sculpture, structures where painting maintenance is undesirable.
Field notes
- Patina needs wet/dry cycling. May be unsuitable for sheltered, continuously wet or chloride/marine sites; coat it or change spec.
- Detail to shed water; avoid crevices, ledges and ponding.
- Use weathering-compatible filler on exposed welds. Run-off stains adjacent concrete.
Material constants
- Modulus of elasticity E: 29,000 ksi
- Shear modulus G: 11,200 ksi
- Density: 490 lb/ft³ (0.284 lb/in³)
- Poisson's ratio: 0.30
- Thermal expansion: 6.5 × 10⁻⁶ in/in/°F
These are the same for every structural steel grade. Strength changes with the specification; stiffness does not.
Related
- ASTM Structural Steel Grades Reference
chemistry, tolerances and the full specification behind this grade
- Steel Shape Properties Table
the sections this grade is supplied in
- Bolt Tensile & Shear Capacity Calculator
fastener grades to match this base metal
- Fillet Weld Strength Calculator
electrode selection to match this base metal
The full specification
Chemistry, tolerances, coatings, galvanizing, weldability, availability and substitutions for every spec: ASTM 101 (STL+).