Scope: what ASTM A516 covers (and what A516M / SA-516 mean)
ASTM A516/A516M is the specification for carbon steel plate intended primarily for welded pressure-vessel-quality steel service at moderate and lower temperatures, where improved notch toughness is important. It is a plate-only specification: the steel is supplied killed, made to fine-grain practice, and ordered against one of four strength grades. The dual designation reflects units, A516 uses inch-pound values and A516M uses SI (metric) values; you cite one system, not both, on a single order.
ASTM A20 doesn't let A516 stand on its own. The umbrella specification ASTM A20/A20M covers general requirements for pressure-vessel plate, and it's the one that fixes the tension-test rules, the permissible variations, the heat-treatment definitions, and the supplementary requirements (S1–S20) that A516 can call on. Think of them as a pair, not two separate documents. A516 handles the grade-specific chemistry and strength; A20 handles how the plate gets tested, marked, and certified.
ASTM A516 vs ASME SA-516: are they the same?
Yes, materially. ASME SA-516 is the ASME Boiler & Pressure Vessel Code Section II, Part A adoption of ASTM A516, with identical chemistry and mechanical requirements. The real difference is jurisdictional. Specify SA-516 when the plate goes into an ASME code-stamped vessel, since the BPVC references the SA- designation. For non-code or general fabrication, specify A516 instead. "A516-70" and "SA516-70" describe the same plate. The prefix just tells the inspector which rule-set you're buying to.
Grades covered: 55, 60, 65 & 70
A516 lays out four grades. That two-digit number is the minimum tensile strength in ksi, Grade 70 means a minimum ultimate tensile of 70 ksi, nothing to do with thickness or carbon content. Push the grade number up and strength rises with it, along with a slightly richer carbon-manganese mix. The tradeoff? Weldability suffers. The tensile and yield strength minima below are the governing acceptance values. Check them against the current A516/A20 edition at order time.
| Grade | Tensile strength | Min. yield (0.2%) | Elongation (typ.) |
|---|---|---|---|
| A516 Gr 55 | 380–515 MPa (55–75 ksi) | ≥205 MPa (30 ksi) | ≈27% in 50 mm |
| A516 Gr 60 | 415–550 MPa (60–80 ksi) | ≥220 MPa (32 ksi) | ≈25% in 50 mm |
| A516 Gr 65 | 450–585 MPa (65–85 ksi) | ≥240 MPa (35 ksi) | ≈23% in 50 mm |
| A516 Gr 70 | 485–620 MPa (70–90 ksi) | ≥260 MPa (38 ksi) | ≈21% in 50 mm |
Elongation requirements track with thickness and come from the A20 tension-test rules: roughly 17–21% in 200 mm (8 in.), and 21–27% in 50 mm (2 in.), highest for Gr 55 and lowest for Gr 70. Grade 70 follows this same A516/A20 framework as the rest of the ladder. It just happens to carry the highest strength minima.
Which A516 grade should I specify?
Grade 70 is the workhorse of pressure-vessel plate, and it's the default for most vessels, boilers and storage tanks. Why? It gives the best strength-to-thickness ratio, which means the thinnest allowable shell. Grade 60 comes into play where a lower design stress or easier weldability is preferred, or where an existing code calculation calls it out. Order the lowest grade that satisfies the design stress. Stepping up the grade adds carbon and raises the carbon equivalent, and that can tighten your welding and preheat controls.
Key chemical requirements
A516 plate is killed, meaning fully deoxidized, and made to fine-grain practice. That's what gives it the even, low-temperature-capable microstructure a pressure vessel actually needs. The chemistry depends on both grade and thickness: carbon and manganese ceilings climb as section thickness increases under the A516/A20 tables. A 50 mm plate, as a result, is allowed richer chemistry than a 12 mm plate of the same grade. Treat the row below as the governing rule. It isn't a frozen specification.
| Element | Limit, A516 Gr 70 (≤12.5 mm basis, wt%) | Note |
|---|---|---|
| Carbon (C) | ≤0.27 (rising to ~0.31 at higher thickness) | killed steel |
| Manganese (Mn) | 0.85–1.20 (wider band at higher thickness) | fine-grain practice |
| Phosphorus (P) | ≤0.025 | residual limit |
| Sulfur (S) | ≤0.025 (lower for HIC service) | low S aids toughness & HIC resistance |
| Silicon (Si) | 0.15–0.40 | deoxidation |
Because carbon and manganese drive the carbon equivalent (CE), A516's chemistry is really a weldability story. A controlled CE is why it welds predictably under common structural practice. For context on how carbon content separates A516 from stainless and Cr-Mo grades, see carbon vs alloy steel.
Key mechanical requirements
The mechanical acceptance values, tensile range, minimum yield, and minimum elongation, come from the per-grade table in A516, applied through the tension-test rules of ASTM A20 (orientation, specimen size, and the elongation basis by thickness). Tensile is given as a range, 485–620 MPa for Grade 70, say, rather than a single minimum. That way both under- and over-strength heats get caught. Yield, on the other hand, is a floor: at least 260 MPa, or 38 ksi, for Grade 70. Each heat gets checked against these values, and the results land on the mill test certificate.
Heat treatment & impact toughness: normalizing rules
A516 ships as-rolled by default. It can be, and often has to be, normalized, reheated above the upper critical temperature, then air-cooled, to refine the grain and boost notch toughness for colder service conditions. Under A20/A516, normalizing turns mandatory past certain section thicknesses. It's also required, as a matter of course, whenever the plate undergoes impact testing for a cold design temperature. For the full mechanism and the thickness logic behind it, see normalizing of PVQ plate.
Buyers most often slip up here by ordering as-rolled plate for a low-temperature vessel, then finding out at inspection that it can't meet the Charpy requirement. If the design metal temperature falls below ambient, specify normalized plate with Charpy testing at the design temperature from the start. Toughness can't be retrofitted after the fact. Put the plate thickness on the inquiry too, since the mechanical minimums and the normalizing trigger both shift with section.
Charpy V-notch impact testing
Low-temperature capability gets proven through Charpy V-notch impact testing, invoked as a supplementary requirement (S5–S8 of A20). You specify the test temperature (e.g. −20 °C, −46 °C) and the minimum absorbed energy; the plate then qualifies for service down to that temperature. This is the heart of A516's "lower-temperature service" claim. The grade number fixes strength, but it's the normalizing-plus-Charpy call-out that fixes toughness. Normalized fine-grain A516 is the standard route to a verified −46 °C vessel plate.
Supplementary requirements & sour-service (HIC) options
A516/A20 isn't a single spec but a menu: you bolt on supplementary requirements to the base order whenever the job calls for them. For pressure-vessel work, a few of these matter more than the rest.
- Vacuum degassing, for cleaner steel and improved toughness/HIC performance.
- Ultrasonic examination (UT), to ASTM A578/SA578 (or A435/A577) for internal soundness; commonly called for on thick or critical plate.
- Simulated post-weld heat treatment (PWHT), test coupons go through the vessel's actual PWHT cycle, so reported properties reflect the plate in its final condition, not before.
- HIC testing per NACE TM0284, resistance to hydrogen-induced cracking for wet-H₂S / sour service.
For plate exposed to wet H₂S (sour service), plain Grade 70 is not enough: specify the HIC-tested variant, evaluated per NACE TM0284 and supplied to meet NACE MR0175 / ISO 15156 where that route is called out. This is a different plate, with tighter sulfur and inclusion control, and must be ordered as such. See NACE MR0175 / ISO 15156 and the detail on sour service & HIC. In our experience, the typical failure is a wet-H₂S separator shell ordered as standard Gr 70 and rejected at review because no HIC report accompanies the heat, call out HIC on the PO, not after rolling.
| Supplementary | Reference | What it adds, when to call it out |
|---|---|---|
| Vacuum degassing | A20 S-series | cleaner steel; low-temp & HIC service |
| Charpy V-notch impact | A20 S5–S8 | qualifies plate for a stated low temperature |
| Ultrasonic examination (UT) | SA578 / A435 / A577 | internal soundness; thick/critical plate |
| HIC test | NACE TM0284 | wet-H₂S / sour service resistance |
| Simulated PWHT | A20 | properties reported in post-weld condition |
Forms covered
ASTM A516 is a plate specification. Plate is the primary and canonical form in which the material gets produced and certified. You can find thinner material as sheet, but A516 is written for, and governs, plate, coil and other long forms sit outside its scope. For help choosing between flat forms, see choosing plate thickness.
Thickness ranges
Nandini Steel keeps A516 plate in stock across Grade 60 and Grade 70, including normalized and NACE-HIC variants, ready for immediate dispatch. Just tell us the thickness you need on your inquiry. That figure drives both the chemistry band and whether normalizing kicks in. We'll confirm available thickness, width and length against current stock by return.
Equivalent specifications
A516 maps approximately onto European and Japanese pressure-vessel plate specifications, not identically. Treat the equivalents below as a starting point for cross-reference and short-listing. Before substituting one for another, check the actual chemistry and mechanical minimums against the governing specification. For the full designation map, see the EN / JIS cross-reference.
| ASTM | ASME | EN 10028-2 (approx.) | JIS G3115 (approx.) |
|---|---|---|---|
| A516 Gr 70 | SA-516 Gr 70 | P355GH | SPV315 |
| A516 Gr 60 | SA-516 Gr 60 | P265GH | SPV235 |
A516 has a counterpart built for higher heat: SA387 Cr-Mo alloy plate. One is the carbon PVQ grade, meant for moderate- and lower-temperature service; the other, a chromium-molybdenum alloy, takes on elevated-temperature, high-pressure duty. A516 falls in the first camp, SA387 in the second. They're distinguished, not interchanged.
Testing, inspection & the mill test certificate
Every A516 plate ships with a mill test certificate (EN 10204 3.1) carrying the heat/cast number, the full ladle chemistry, the mechanical test results (tensile, yield, elongation, and any Charpy data), and the heat-treatment condition (as-rolled or normalized). If an independent third-party release is required, specify EN 10204 3.2 instead.
The document's structure is laid out in how to read a mill test certificate, while the standard itself is covered in the EN 10204 3.1 mill test certificate node. The MTC remains the buyer's primary record for traceability.
The MTC is where heat/cast traceability becomes real: the stamped heat number on the plate ties straight back to the certificate and the mill. Nandini Steel includes the EN 10204 3.1/3.2 MTC with every order, and it also supports additional release documentation when those supplementary requirements are called out: UT per SA578, PMI, and HIC reports per NACE TM0284. See testing, MTC & NDT and heat/cast traceability for the inspection chain.
Applications: where A516 plate is used
A516, and its code twin SA-516, has become the go-to plate for welded carbon-steel pressure equipment.
- Pressure vessels & boilers, shells, heads and drums; this is the primary use, with boiler-quality plate covering the boiler case.
- Oil & gas, separators, knock-out drums and sour-service vessels. That's the HIC-tested route.
- Petrochemical, process columns, exchangers and storage.
- Storage tanks and separators for moderate- and lower-temperature service.
How to order A516 plate to spec
A516 orders live or die at the call-out. Get these right, in order, and the plate shows up certified to exactly what the vessel needs:
- Grade, 55 / 60 / 65 / 70 (70 is the default).
- Specification designation, A516 (general) or SA-516 (ASME code-stamped vessel).
- Heat-treat condition, as-rolled or normalized (normalized for low-temperature or thick section).
- Charpy requirement, test temperature and minimum energy, if impact-tested.
- HIC / sour service, HIC per NACE TM0284 to MR0175/ISO 15156, if wet-H₂S.
- MTC level, EN 10204 3.1 or 3.2.
- UT, per SA578 acceptance class, if required.
- Thickness, width, length and quantity, thickness drives chemistry and the normalizing trigger.
| Call-out | Options | Default / note |
|---|---|---|
| Grade | 55 / 60 / 65 / 70 | 70, the workhorse |
| Designation | A516 / SA-516 | SA-516 for code vessels |
| Condition | as-rolled / normalized | normalized for low-temp / thick |
| Charpy | temp + energy | e.g. −46 °C |
| HIC | NACE TM0284 | wet-H₂S only |
| MTC | 3.1 / 3.2 | 3.1 standard |
Order to this spec from the conforming plate pages: A516 Grade 70 plate is the workhorse. There's also A516 Gr 60 plate, normalized A516 plate for low-temperature vessels, and A516 HIC-tested plate for sour service. Need variants, sizes, or the plate weight calculator? The A516 Grade 70 hub has all of it. For the step-by-step, see how to specify A516 for a vessel.
FAQ
Is A516 the same as SA516?
What does the number in A516 Grade 70 mean?
When does A516 plate have to be normalized?
What is A516 Grade 70 tensile and yield strength?
How do I order A516 for sour (wet H₂S) service?
What is the European equivalent of A516 Grade 70?
Request a quote for A516 plate
Nandini Steel has held ISO 9001:2015 certification since it started stocking, supplying and exporting A516 / SA-516 pressure-vessel plate. The company carries Grade 60 and Grade 70, including normalized and NACE-HIC variants, and keeps them ex-stock for immediate dispatch. Every order ships with an EN 10204 3.1/3.2 mill test certificate.
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Send your grade, condition, Charpy/HIC and MTC call-outs along with thickness and quantity for a live quote. See standards & specifications or contact us.