ASTM A53 Gr A — Yield Strength, Tensile Strength and Applications
ASTM A53 Grade A: Fy 30 ksi, Fu 48 ksi (specified minimums). The standard spec for round pipe used structurally. Grade B is the structural grade. Black or hot-dip galvanized, welded (Type E) or seamless (Type S). Sized by Nominal Pipe Size (NPS) and weight class (Std, XS, XXS: Standard, Extra Strong, Double Extra Strong).
Strength
| Grade | Fy (ksi) | Fu (ksi) | Note |
|---|---|---|---|
| A | 30 | 48 | Lower strength; less common structurally. |
Fy and Fu are specification minimums. Verify the grade on the Mill Test Report (MTR); dual-certified material is common.
Applicable members
Pipe (round)
Preferred for: Pipe.
Applicable is not the same as stocked. Confirm availability with the supplier.
Common applications
Pipe columns, posts, railings, bollards, struts, handrail, exposed round members.
Field notes
- Grade B (Fy 35 ksi) is the A53 grade recognized for structural design under American Institute of Steel Construction (AISC) 360; do not design to Grade A unless certified.
- AISC lists A53 Grade B Type E or S. Type F (furnace-butt-welded) is not an AISC-approved structural material.
- AISC 360 B4.2 design rule: design wall = 0.93 × nominal (AISC tables already reflect this).
- Sold by NPS and Std/XS/XXS; confirm the weight class matches the design.
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+).