ASTM A519 Seamless Mechanical Tubing
2026/03/09
ASTM A519 Seamless Mechanical Tubing
ASTM A519/A519M is the standard specification for seamless carbon and alloy steel mechanical tubing, covering hot‑finished and cold‑finished products for mechanical, structural, and pressure applications. It defines strict chemical composition, mechanical properties, manufacturing, and testing requirements for round, square, rectangular, and special‑section tubes up to 12 3⁄4 in. (325 mm) OD.
1. Standard Overview
- Scope: Seamless carbon/alloy steel mechanical tubing (hot‑finished/cold‑finished) for mechanical engineering, pressure service, automotive, machinery, and structural components.
- Manufacturing: Produced via hot working (piercing/rolling) with optional cold finishing for tight dimensional control and enhanced properties.
- Testing: Mandatory tension, flattening, flaring, hardness, hydrostatic/nondestructive electric tests.
- Key Grades: Low‑carbon (1010, 1020), medium/high‑carbon (1045), alloy (4130, 4140),
2. Chemical Composition
|
Grade |
C |
Mn |
P (max) |
S (max) |
Si |
Cr |
Mo |
|---|---|---|---|---|---|---|---|
| 1010 | 0.08–0.13 | 0.30–0.60 | 0.040 | 0.050 | — | — | — |
| 1020 | 0.18–0.23 | 0.30–0.60 | 0.040 | 0.050 | 0.15–0.35 | — | — |
| 1045 | 0.43–0.50 | 0.60–0.90 | 0.040 | 0.050 | 0.10–0.35 | — | — |
| 4130 | 0.28–0.33 | 0.40–0.60 | 0.040 | 0.050 | 0.15–0.35 | 0.80–1.10 | 0.15–0.25 |
| 4140 | 0.38–0.43 | 0.75–1.00 | 0.040 | 0.050 | 0.15–0.35 | 0.80–1.10 | 0.15–0.35 |
3. Mechanical Properties (Minimum Values)
|
Grade |
Condition |
Tensile Strength (MPa) |
Yield Strength (MPa) |
Elongation (%) |
Hardness (HB, max) |
|---|---|---|---|---|---|
| 1020 | Annealed (A) | 331 | 193 | 30 | 143 |
| 1020 | Normalized (N) | 379 | 234 | 22 | 156 |
| 1020 | Cold‑drawn (CW) | 483 | 414 | 5 | 197 |
| 1045 | Normalized | 586 | 345 | 15 | 217 |
| 4130 | Quenched & Tempered | 621 | 483 | 18 | 241 |
| 4140 | Quenched & Tempered | 855 | 689 | 10 | 285 |
4. Key Features & Applications
- Precision: Tight dimensional tolerances (OD, ID, wall thickness) for mechanical assemblies.
- Strength: Balanced strength‑ductility; alloy grades offer high fatigue/toughness.
- Versatility: Hot‑finished (cost‑effective) or cold‑finished (precision) options
- Applications: Automotive shafts, hydraulic cylinders, machine components, structural parts, pressure vessels.
