Selection summary
Overview
ASTM A516/A516M Grade 70 is a pressure-vessel plate specification with strength, chemistry, heat-treatment, testing, and supplementary requirements tied to plate thickness and the construction code. It should not be purchased as generic Grade 70 plate.
This page separates standard-oriented limits from typical reference data. Purchase acceptance comes from the ordered specification and certified material test report.
Names and systems
Identity & standards
Similar designations across ASTM, EN, JIS, and other systems are not automatically interchangeable. Product form and ordered standard control chemistry, properties, dimensions, condition, and testing.
Reference chemistry
Composition
| Element | Reference range | Why it matters |
|---|---|---|
| Carbon | Thickness-dependent maximum | Strength and weldability control |
| Manganese | Grade- and thickness-dependent | Strength and toughness |
| Silicon | Controlled range | Deoxidation and strength |
Concise grade-family reference only. Confirm every element limit against the current standard for the exact product ordered.
Condition matters
Reference properties
Common Grade 70 plate requirement; verify thickness and current specification
Specified Grade 70 range; product thickness and heat treatment apply
Typical carbon-steel reference value, not an acceptance criterion
Environment first
Corrosion behavior
A516 Grade 70 is not inherently corrosion resistant; process chemistry, corrosion allowance, lining, cladding, or coating may be required.
Hydrogen service, sour service, wet H2S, and high-temperature hydrogen attack need code- and process-specific material controls.
Temperature, concentration, deposits, crevices, stress, surface finish, cleaning, and fabrication quality can change service performance.
Service limits
Temperature & service
Use construction-code allowable stresses rather than room-temperature minimums for design.
Delivery condition
Heat treatment & condition
A516 Grade 70 plate can be ordered in as-rolled or heat-treated conditions permitted by thickness and specification; normalizing requirements must be checked against the current edition and purchase order.
Construction-code postweld heat treatment is separate from mill delivery heat treatment; simulated PWHT testing may need to be ordered when final properties must represent the fabrication cycle.
Process route
Fabrication
Welding procedure, preheat, postweld heat treatment, toughness, and forming depend on thickness and construction code.
Normalized delivery, impact testing, simulated postweld heat treatment, and ultrasonic testing may need to be ordered.
Magnetic response: Ferromagnetic.
Decision boundaries
Comparisons & substitution
A516 Grade 70 is a pressure-vessel plate specification, not a generic substitute for structural Grade 50 or 70 steel.
Lower A516 strength grades, low-temperature grades, Cr-Mo steels, clad plate, or stainless steel can be appropriate when toughness, temperature, hydrogen, or corrosion governs.
Where it is used
Applications
Ordering scope
Product forms & standards
Carbon-steel plate for welded pressure vessels under ASTM A516/A516M and the invoked ASTM A20/A20M general requirements.
Heads, shells, forgings, pipe, fittings, and bolting require their own construction-code material specifications.
State thickness, heat treatment, impact-test temperature, PWHT simulation, ultrasonic examination, supplementary requirements, and construction code.
Decision support
Selection guidance
Choose this grade when
- A recognized carbon-steel pressure-vessel plate with Grade 70 strength is required.
- The purchase order can state construction code, heat treatment, impact testing, and supplementary requirements.
Review another grade when
- Low-temperature toughness, sour service, hydrogen exposure, or elevated temperature controls selection.
- Clad plate, alloy steel, or stainless steel is needed for corrosion or temperature.
Before ordering
Procurement checklist
State the exact material and product specification, edition, grade, dimensions, tolerances, and delivery condition.
Require heat identity and a material test report showing chemistry, mechanical tests, and any ordered supplementary tests.
Confirm fabrication route, welding or heat treatment, inspection, marking, corrosion protection, export packing, and destination requirements.
State the construction code, plate heat treatment, impact-test temperature, PWHT simulation, and ultrasonic examination.
Traceable evidence