A516 Grade 70 steel (K02700): properties, composition, equivalents
ASTM A516 Grade 70 / ASME SA-516-70 (UNS K02700): the standard US pressure-vessel plate — 260 MPa (38 ksi) yield, 485–620 MPa (70–90 ksi) tensile, normalized for toughness. Grades 55–70, composition by thickness, HIC/NACE options, P265GH/P295GH/Q345R equivalents.
What is A516 Grade 70?
ASTM A516 Grade 70 (ASME SA-516-70) is the plate that most of the world's carbon-steel pressure vessels are made from: a killed, fine-grain carbon-manganese steel with 260 MPa (38 ksi) minimum yield and 485–620 MPa (70–90 ksi) tensile, UNS K02700. A516 covers Grades 55, 60, 65 and 70 (numbers = minimum tensile in ksi); Grade 70 is the default because its ASME allowable stress of 138 MPa (20 ksi) gives the thinnest wall for the money.
The title says 'moderate and lower temperature service': fine-grain aluminium-killed practice and normalizing (mandatory above 40 mm, optional but usual below) give the toughness that lets normalized Grade 70 certify Charpy values at −45 °C and below — hence its use in LPG bullets and spheres, air receivers, refinery drums, heat-exchanger shells and channels, storage vessels and cold-climate equipment. A515 is the coarse-grain sister for higher temperature; A537 the normalized upgrade for 345 MPa; A285 the low-pressure economy grade.
Sour and hydrogen service is handled by ordering HIC-resistant A516-70 (S ≤ 0.002 %, Ca-treated, NACE TM0284 tested) — a large share of refinery orders. European P295GH/P265GH, Chinese Q345R/Q245R and JIS SB450/SPV315 are the near matches; none is identical, so cross-supplied plate needs code appraisal.
A516 Grade 70 chemical composition
| Element | Mass % | Note |
|---|---|---|
| C | ≤ 0.27 | Grade 70: ≤ 12.5 mm 0.27; 12.5–50 mm 0.28; 50–100 mm 0.30; 100–200 mm 0.31. Grade 60: 0.21–0.25; Grade 65: 0.24–0.29; Grade 55: 0.18–0.26 |
| Mn | 0.85 – 1.2 | Grade 70 plate > 12.5 mm: 0.85–1.20 (heat), 0.79–1.30 (product); ≤ 12.5 mm: 0.60–0.90 |
| P | ≤ 0.025 | |
| S | ≤ 0.025 | HIC-resistant orders: S ≤ 0.002–0.005, Ca treated |
| Si | 0.15 – 0.4 |
ASTM A516/A516M-17 Table 1 (heat analysis). Residuals per A20 (Cu ≤ 0.40, Ni ≤ 0.40, Cr ≤ 0.30, Mo ≤ 0.12, V ≤ 0.03, Nb ≤ 0.02 when not specified). Killed, fine-grain practice (Al) is mandatory — grain size 5 or finer.
A516 Grade 70 mechanical properties
| Thickness / condition | Yield strength ReH / Rp0.2 MPa (ksi) | Tensile strength Rm MPa (ksi) | Elongation A % | Hardness |
|---|---|---|---|---|
| Grade 70 — all thicknesses (as-rolled ≤ 40 mm; normalized > 40 mm) | 260 (37.7) | 485–620 (70.3–89.9) | 17 (L0 200 mm) / 21 (50 mm) | ≈ 140–180 HB (typ.) |
| Grade 65 | 240 (34.8) | 450–585 (65.3–84.8) | 19 / 23 | — |
| Grade 60 | 220 (31.9) | 415–550 (60.2–79.8) | 21 / 25 | — |
| Grade 55 | 205 (29.7) | 380–515 (55.1–74.7) | 23 / 27 | — |
| Grade 70 — typical mill certificate, normalized 25 mm | ≈ 300–340 (≈ 43.5–49.3) | ≈ 520–560 (≈ 75.4–81.2) | ≈ 28–32 (50 mm) | ≈ 150–165 HB |
| Grade 70 — ASME II-D allowable stress at 20–340 °C | S = 138 MPa (20 ksi) (S = 20.0 MPa (2.9 ksi)) | — | — | — |
| Grade 70 — allowable stress at 425 °C (800 °F) | S ≈ 100 MPa (14.5 ksi) (S ≈ 14.5 MPa (2.1 ksi)) | — | — | — |
ASTM A516/A516M-17 Table 2; elongation in 200 mm or 50 mm. Yield is a minimum, tensile a range. Charpy is not mandatory in A516 but is required by ASME VIII (UCS-66) below the exemption curve — order S5 with test temperature; normalized Grade 70 typically gives 27 J at −45 °C or lower.
Impact toughness
A516 Grade 70 requires a minimum Charpy V-notch energy of 27 J at -45 °C (typical, normalized ≤ 50 mm; not a default requirement). A516 is the 'lower-temperature' carbon plate (vs A515 for higher temperature): fine-grain, normalized material commonly certifies 20 J at −50 °C (ASME UCS-66 curve D exemptions), which is why it dominates LPG, refrigerant and cold-climate vessels.
A516 Grade 70 equivalent grades
| Grade | System | Match | Why / differences |
|---|---|---|---|
| A516 Gr. 60 | ASTM / ASME | Near | Same spec, lower strength (220 MPa / 415–550 MPa); chosen for better toughness and formability. |
| A537 Cl. 1 | ASTM / ASME | Near | Normalized C-Mn-Si plate, yield 345 MPa — the upgrade when A516-70 is not strong enough. |
| P295GH | EN (European) | Near | EN 10028-2 P295GH (1.0481, ex 17Mn4): yield 295 MPa, Rm 460–580 MPa, guaranteed yield to 400 °C — strength closest to A516-70; chemistry C ≤ 0.08–0.20 lower. |
| P265GH | EN (European) | Near | Yield 265 MPa, Rm 410–530 MPa — the EN grade most often substituted for A516-60/65; slightly weaker than Grade 70. |
| P355GH / P355NH | EN (European) | Near | 355 MPa grades exceed A516-70 yield; used when a European mill supplies a Grade 70 design. |
| Q345R | GB/T (China) | Near | GB/T 713 Q345R: yield 345 MPa, Rm 510–640 MPa, 31 J at 0 °C — the Chinese pressure plate normally offered for A516-70 (stronger); Q245R ≈ A516-60. |
| 16GS / 17GS / 20K | GOST (Russia/CIS) | Near | GOST 5520 boiler plates: 16GS (yield 265–295, Rm 460–490), 17GS (345 / 490), 20K (245 / 410). |
| IS 2002 Gr. 2 / Gr. 3 | IS (India) | Near | IS 2002 grade 2 (yield 240, Rm 410–530) and 3 (yield 290, Rm 490–610). |
| SB450 / SPV315 | JIS (Japan) | Near | JIS G3103 SB450 boiler plate (yield 245, Rm 450–590) and G3115 SPV315 (yield 315, Rm 490–610) bracket A516-70. |
| A36 | ASTM / ASME | Functional | Structural plate without pressure-vessel quality (grain size, testing, chemistry control) — not accepted for ASME pressure parts except by special provisions. |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check. Full cross-reference for A516 Grade 70 →
Old and superseded designations
| Old name | Standard | Note |
|---|---|---|
| K02700 (Gr 70), K02403 (Gr 60), K02800 (Gr 65), K01800 (Gr 55) | UNS | |
| SA-516 | ASME BPVC Section II Part A | ASME adoption — identical to A516 with ASME editorial changes; the form used on vessel drawings. |
| A515 | ASTM A515 | Sister spec for intermediate/higher temperature (coarse-grain Si-killed); A516 replaced it for most work. |
| A285 Gr. C | ASTM A285 | Lower-strength, lower-quality vessel plate for low-pressure tanks. |
| BS 1501-224 Gr 490 | BS 1501 (withdrawn) | British counterpart. |
Product forms and tolerance standards
Product forms: plate (only) — as-rolled ≤ 40 mm, normalized > 40 mm (or when specified), heads, shells and nozzles cut from plate, clad plate base (A263/A264/A265), HIC-resistant and NACE-tested variants (supplementary S-requirements, low S/P, Ca treatment).
Dimensional tolerances: plate: ASTM A20/A20M (thickness, flatness, UT per A435/A578 when ordered); surface: A20; edges per A20.
Key property values
A516 Grade 70 yield strength
Minimum 260 MPa (38 ksi) for all thicknesses; typical normalized plate 300–340 MPa. Grade 65: 240 MPa; Grade 60: 220 MPa; Grade 55: 205 MPa.
A516 Grade 70 tensile strength
485–620 MPa (70–90 ksi); typical 520–560 MPa. Grade 65: 450–585; Grade 60: 415–550; Grade 55: 380–515 MPa.
ASME allowable stress
SA-516-70: 138 MPa (20.0 ksi) from −29 to 340 °C, 131 MPa at 370 °C, 118 MPa at 400 °C, ≈ 100 MPa at 425 °C; maximum code temperature 538 °C (1000 °F) with reduced allowables (creep range above ~400 °C). Not for prolonged use above 425 °C (graphitization).
Elongation and hardness
≥ 17 % in 200 mm / ≥ 21 % in 50 mm (typical 28–32 %). Hardness not specified; typical 140–180 HB. NACE MR0175 (≤ 22 HRC / 237 HB) is met by base metal; weld HAZ must be controlled by PWHT.
Impact toughness
Not mandatory, but ASME VIII UCS-66 exempts normalized A516 (curve D) to lower MDMTs than as-rolled (curve B); normalized Grade 70 typically gives ≥ 27 J at −45 °C for ≤ 50 mm. Order supplementary S5 with the required temperature and energy (e.g. 20 J at −46 °C for LPG).
Heat treatment
Normalize 870–930 °C (1600–1700 °F), air cool — mandatory > 40 mm, and above 25 mm when Charpy is required. Stress relief / PWHT 595–650 °C (1100–1200 °F), 1 h per 25 mm — required by ASME VIII above 38 mm (32 mm without preheat) and for lethal, sour and caustic service regardless of thickness.
Physical properties
Density 7.85 g/cm³, E = 200 GPa, expansion 11.7 × 10⁻⁶/K (6.5 × 10⁻⁶/°F), conductivity ≈ 50 W/m·K.
Weldability
Very good weldability (CE ≈ 0.40–0.45 for Grade 70; supplementary S-requirements can cap it). ASME IX-qualified procedures with E7018 / ER70S-6 / F7A2-EM12K; preheat 10 °C ≤ 25 mm, 80 °C to 38 mm, 95–120 °C above (ASME VIII UCS-56 / typical fabricator practice). PWHT 595–650 °C required by code above 38 mm and for wet H₂S, amine, caustic and lethal service. Low-hydrogen practice mandatory for HIC-resistant material; limit HAZ hardness to 248 HV for sour service.
Machining, forming and heat treatment
Machinability ≈ 65–70 % of B1112 — drilling and boring of nozzles, flanges and tubesheets are routine. Cold forming of heads and shells: strain ≤ 5 % without post-forming heat treatment (ASME UCS-79), otherwise normalize; hot forming 870–1100 °C followed by normalizing when required. Flame cutting standard; grind cut edges and check for laminations (A435/A578 UT for critical plate).
Typical applications
- Pressure vessels, separators, reactors and drums (ASME VIII Div. 1 and 2)
- LPG and ammonia storage spheres, bullets and road tankers (normalized, Charpy-tested)
- Heat-exchanger shells, channels, tubesheets and covers (TEMA)
- Boiler drums and headers at moderate temperature, air receivers
- Refinery and gas-plant equipment in sour service (HIC-resistant A516-70)
- Storage tanks (API 650 Group III/IV) and low-temperature tanks
- Clad-plate base for stainless or nickel-alloy lined vessels
Frequently asked questions
What is the difference between A516 Grade 60 and Grade 70?
Strength: Grade 60 has 220 MPa yield / 415–550 MPa tensile (60 ksi), Grade 70 has 260 MPa / 485–620 MPa (70 ksi). Grade 70 gives a thinner wall (ASME allowable 138 vs 118 MPa); Grade 60 has slightly more carbon headroom for toughness and is preferred by some for very low temperature or heavy forming. Most vessels use Grade 70.
What is the difference between A516 and SA-516?
None in substance. SA-516 is the ASME Boiler and Pressure Vessel Code adoption of ASTM A516 (Section II Part A); vessel drawings cite SA-516 because ASME requires ASME-adopted specifications. Mills certify plate to both.
Is A516 Grade 70 normalized?
Mandatory for plate over 40 mm (1.5 in); optional but almost universal below that when Charpy testing is specified, because normalizing moves the plate to ASME UCS-66 curve D and allows lower design temperatures. Order 'normalized' explicitly for LPG and cold service.
What is the European equivalent of A516 Grade 70?
No exact match. P295GH (EN 10028-2, 295 MPa yield) is closest in strength; P265GH is often supplied for Grade 60/65 designs; P355GH or P355NH exceed it. For PED equipment the substitution needs a particular material appraisal; for ASME vessels the plate must be SA-516 or an accepted equivalent.
What is the maximum temperature for A516 Grade 70?
ASME lists allowables to 538 °C (1000 °F), but carbon steel is generally limited to about 425 °C (800 °F) for long-term service because of graphitization and creep; above that use A204 (C-½Mo) or A387 (Cr-Mo) grades.
What is HIC-resistant A516-70?
A516 Grade 70 melted with very low sulphur (≤ 0.002 %), calcium treatment for inclusion shape control, low P and often low Mn, and tested to NACE TM0284 for hydrogen-induced cracking. It is specified for wet H₂S (sour) service in refineries and gas plants per NACE MR0175/ISO 15156 and MR0103.
Related grades
Verified against ASTM A516/A516M-17; ASTM A516/A516M-17 Tables 1–2; ASTM A20/A20M-22; ASME BPVC II-D (allowable stresses); ASME BPVC VIII-1 UCS-56 / UCS-66; NACE TM0284 / MR0175. Last checked: September 2026.