A516 Gr.70 Steel
A carbon steel plate for pressure vessels
Typical values for the temper in the title
A516 Gr.70 is the most common plate steel for welded pressure vessels. It is a carbon-manganese steel with good notch toughness, intended for moderate and lower-temperature service. The 70 is the minimum tensile strength: 70 ksi (485 MPa).
It is used for pressure vessels, boilers, heat exchangers and storage tanks (per API 650 and 620). Plates thicker than 1.5 inch (about 38 mm) are supplied normalized. In ASME it is called SA-516.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 485-620 MPa | |
| Yield strength Rp0.2 | 260 MPa | |
| Elongation A | 17% | |
| Hardness | 145-175 HB | |
| Modulus of elasticity E | 207 GPa | |
| Density ρ | 7.85 g/cm³ | |
| Machinability | 60% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| C carbon | max 0.27 (to ½"), 0.28 (½–2"), 0.30 (2–4"), 0.31 (over 4") | strength; rises with thickness |
| Mn manganese | 0.85–1.20 | |
| Si silicon | 0.15–0.40 | |
| P phosphorus | max 0.025 | |
| S sulfur | max 0.025 | |
| Fe iron | balance |
Ranges per ASTM A516 (heat analysis).
Conditions and heat treatment
Structural, pressure and pipeline steels are selected by minimum yield strength and impact toughness at a given temperature, not by a heat treatment the user performs. The delivery condition is defined by the standard.
| Condition | Properties | When to choose it |
|---|---|---|
| As rolled or normalized | yield min 260 MPa, Rm 485–620 MPa | elongation min 21% (2") or 17% (8") |
| Normalized | mandatory above 1.5" (about 38 mm) | improved toughness |
| Impact testing (S5) | optional supplementary requirement | for cold service |
Applications
- Pressure vessels
- Boilers and heat exchangers
- Storage tanks (API 650 / 620)
- Petrochemical reactors
- Welded vessels and piping
Fabrication
Welding
Welds well. In thick sections, post-weld stress relief is sometimes performed, per the design code.
Hot service
Suitable for moderate temperatures. For high temperature and hydrogen service, Cr-Mo steels such as A387.
Corrosion
A carbon steel: a corrosion allowance or protection is needed in design.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| A387 Gr.22 | 515-690 / 310 MPa | Difficult — PWHT mandatory! | Cr-Mo for high-temperature service · material page |
| S355 | 470–630 / 355 MPa | Good | a structural steel, not a pressure steel · material page |
| A36 | 400–550 / 250 MPa | Excellent | a structural steel, without pressure vessel requirements · material page |
Common mistakes
Substituting a structural steel in a pressure vessel
The design code requires a pressure steel with suitable certification and requirements.
Forgetting an impact requirement for cold service
For cold service, add the S5 requirement.
Using A516 in hot hydrogen service
In such conditions selection follows API 941, usually a Cr-Mo steel.
Equivalents, standards and supply
| ASTM | A516 Gr.70 |
|---|---|
| Standards | ASTM A516 / ASME SA-516 |
| Forms | plate only |
| Producers | Dillinger · Industeel · Nucor · NLMK |
Learn more
Values are typical and for comparison only, and depend strongly on condition and diameter. For design, rely on the standard and on the mill certificate. Sources: SAE J403 and J404, ASTM A29, A322 and A519 (composition), producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026