A500 is the structural spec — it certifies minimum yield and tensile strength for load-bearing construction. A513 is the mechanical spec — it controls chemistry and dimensions for parts, frames, and anything machined, plated, or precision-fit. Same mills, same shapes; different guarantees.
If an engineer sized the tube to carry load — building frames, columns, supports, anything referencing HSS or a minimum yield strength — specify A500. If the tube is a component — machined, plated, welded into an OEM assembly, or precision-fit — specify A513. A500 guarantees strength; A513 guarantees precision.
| ASTM A500 · Structural | ASTM A513 · Mechanical | |
|---|---|---|
| What it certifies | Minimum yield & tensile strength | Chemistry & dimensional control |
| Grades | Grade B (Fy 46 KSI) · Grade C (Fy 50 KSI) | 1008 – 1020 · Type 1 & Type 2 |
| OD tolerance, 2″ round | ±0.5–0.75% of OD (≈ ±0.010″–0.015″) | ±0.005″–0.006″ |
| Typical calls | Building frames, columns, equipment supports, bridges | Automotive & OEM parts, ag equipment, conveyors, fitness & furniture |
| Galvanized counterpart | ASTM A1076 | ASTM A787 |
| Standard | ASTM A500/A500M-23 | ASTM A513/A513M-24 |
| Shapes & sizes at MMC | Round 1″–3½″ OD · Square ½″–5″ · Rectangular to 4″×6″ · Wall 0.035″–0.250″ | |
Full mechanical, chemistry, and tolerance tables on the A500 spec page and A513 spec page.
The drawing references HSS dimensions, a minimum yield strength (Fy 46 or 50 KSI), or structural and building applications. A500's certified mechanical properties are what the engineer's calculations rely on — never substitute down.
The tube gets machined, plated, painted, telescoped, or assembled into a product where fit and finish matter. A513's tighter OD control and choice of hot-rolled (Type 1) or cold-rolled (Type 2) strip are built for components.
Not when the design depends on guaranteed strength. A500 certifies minimum yield and tensile properties (Grade B: 46 KSI yield for shapes; Grade C: 50 KSI); A513 controls chemistry and dimensions but does not certify minimum mechanical properties. If the drawing calls out A500, HSS, or a minimum yield strength, order A500.
A513. On a 2″ round, A513 holds ±0.005″–0.006″ OD, while A500 allows ±0.5%–0.75% of the OD — about ±0.010″–0.015″. That's why machined, plated, and precise-fit parts are ordered to A513.
Look for the cues. HSS dimensions, a named yield strength (Fy 46 or 50 KSI), or structural/building references point to A500. References to grade chemistry (1008–1020), Type 1 or Type 2, surface finish, or machining and plating operations point to A513. When in doubt, send us the drawing — we run both specs on the same mills.
It depends on grade, size, wall, and quantity rather than the spec itself — both run on the same five ERW mills in the same size envelope. Send the spec and quantity and we'll quote it both ways if your application allows either.
Each spec has a precoated counterpart: ASTM A787 is the galvanized equivalent of A513 mechanical tubing, and ASTM A1076 is the galvanized structural option with A500-style tolerances. Major Metals manufactures both.
At Major Metals, yes — both run in round 1″–3½″ OD, square ½″–5″, and rectangular to 4″×6″, wall 0.035″–0.250″, in mill lengths 5–40 ft.
We manufacture both specs on the same five mills in Mansfield, Ohio. Send your print or spec and we'll confirm the right call — with a quote to match.
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