Steel Standart

A333 Grade 6 equivalent grades: ASTM, EN, JIS, GB, DIN

A333 Grade 6 is carbon steel pipe for low-temperature service, impact tested at −45 °C specified in ASTM A333. Every grade in the database that can stand in for it is listed below, drawn from 4 standard systems, each with the reason it does or does not match exactly. The full A333 Grade 6 data sheet carries the composition and mechanical tables.

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Mills routinely dual-certify A333 Grade 6 as STPL380 — the limits sit inside each other in both directions. A106 Grade B, P275NL1 differ on one limit only — a carbon ceiling, an impact temperature or a strength minimum. 316L, A53 Grade B, A516 Grade 70 and 2 more serve in the same applications, but the composition differs enough that the engineer signs it off, not the buyer. The table holds 1 in JIS (Japan), 5 in ASTM / ASME, 1 in EN (European), 1 in AISI / SAE.

Cross-reference table

A333 Grade 6 equivalents by system
GradeSystemMatchWhy / differences
STPL380JIS (Japan)IdenticalJIS G3460 STPL380: 215 MPa minimum yield, 380 MPa minimum tensile, carbon steel pipe for low-temperature service impact tested at −45 °C. The Japanese counterpart to Grade 6, marginally lower in strength. STPL450 and STPL690 correspond to the nickel grades.
A106 Grade BASTM / ASMENearIdentical minima — 240 MPa yield, 415 MPa tensile — and a very similar analysis including the 0.10 % silicon minimum. The difference is the one that matters here: **A106 requires no impact test**, so it carries no documented toughness at any temperature. A333 Grade 6 is, in effect, A106 Grade B with a mandatory Charpy test at −45 °C and tighter phosphorus and sulphur.
P275NL1EN (European)NearEN 10216-4 P275NL1: 275 MPa minimum yield, normalised seamless tube for low-temperature service, impact tested at −40 °C; P275NL2 is tested at −50 °C. Slightly stronger than Grade 6 with a comparable toughness requirement — the direct European counterpart for carbon-steel cryogenic-adjacent piping.
316LAISI / SAEFunctionalAustenitic stainless steel has no ductile-to-brittle transition, so it needs no impact test at cryogenic temperature and is often the alternative to a nickel steel below about −100 °C. It costs several times more and has a much higher thermal expansion.
A53 Grade BASTM / ASMEFunctionalASTM A53 Grade B: the same strength again, but with no silicon minimum, looser phosphorus and sulphur and no impact test. It is the general-service pipe at this strength level and has no place in low-temperature work.
A516 Grade 70ASTM / ASMEFunctionalThe low-temperature plate counterpart. A516 Grade 70 plate and A333 Grade 6 pipe are the pair normally used together in a cold vessel and its piping — the plate at 260 MPa yield and 485–620 MPa tensile, impact tested when ordered to supplementary requirement S5 or to the vessel code's curves.
A333 Grade 3ASTM / ASMEFunctional3.5 % nickel, 450 MPa tensile, impact tested at −101 °C. The grade to move to when −45 °C is not cold enough; Grade 7 (2.5 % Ni, −75 °C) and Grade 9 (2 % Ni + Cu, −100 °C) sit between.
A333 Grade 8ASTM / ASMEFunctional9 % nickel, 515 MPa yield, impact tested at **−195 °C** — the LNG grade. A different class of steel entirely, quenched and tempered, far more expensive, and welded with nickel-base consumables.

Identical, near and functional are defined once on the grade index; the reason column below says which limit differs in each case.

A333 Grade 6 in JIS (Japan)

  • STPL380 — Identical JIS G3460 STPL380: 215 MPa minimum yield, 380 MPa minimum tensile, carbon steel pipe for low-temperature service impact tested at −45 °C. The Japanese counterpart to Grade 6, marginally lower in strength. STPL450 and STPL690 correspond to the nickel grades.

A333 Grade 6 in ASTM / ASME

  • A106 Grade B — Near Identical minima — 240 MPa yield, 415 MPa tensile — and a very similar analysis including the 0.10 % silicon minimum. The difference is the one that matters here: **A106 requires no impact test**, so it carries no documented toughness at any temperature. A333 Grade 6 is, in effect, A106 Grade B with a mandatory Charpy test at −45 °C and tighter phosphorus and sulphur.
  • A53 Grade B — Functional ASTM A53 Grade B: the same strength again, but with no silicon minimum, looser phosphorus and sulphur and no impact test. It is the general-service pipe at this strength level and has no place in low-temperature work.
  • A516 Grade 70 — Functional The low-temperature plate counterpart. A516 Grade 70 plate and A333 Grade 6 pipe are the pair normally used together in a cold vessel and its piping — the plate at 260 MPa yield and 485–620 MPa tensile, impact tested when ordered to supplementary requirement S5 or to the vessel code's curves.
  • A333 Grade 3 — Functional 3.5 % nickel, 450 MPa tensile, impact tested at −101 °C. The grade to move to when −45 °C is not cold enough; Grade 7 (2.5 % Ni, −75 °C) and Grade 9 (2 % Ni + Cu, −100 °C) sit between.
  • A333 Grade 8 — Functional 9 % nickel, 515 MPa yield, impact tested at **−195 °C** — the LNG grade. A different class of steel entirely, quenched and tempered, far more expensive, and welded with nickel-base consumables.

A333 Grade 6 in EN (European)

  • P275NL1 — Near EN 10216-4 P275NL1: 275 MPa minimum yield, normalised seamless tube for low-temperature service, impact tested at −40 °C; P275NL2 is tested at −50 °C. Slightly stronger than Grade 6 with a comparable toughness requirement — the direct European counterpart for carbon-steel cryogenic-adjacent piping.

A333 Grade 6 in AISI / SAE

  • 316L — Functional Austenitic stainless steel has no ductile-to-brittle transition, so it needs no impact test at cryogenic temperature and is often the alternative to a nickel steel below about −100 °C. It costs several times more and has a much higher thermal expansion.

Superseded names for A333 Grade 6

  • ASME SA-333 Grade 6 — ASME BPVC Section II Part A: Not a different material — the ASME adoption of the same specification, for use inside the Boiler and Pressure Vessel Code. Pipe is commonly dual-marked A333/SA-333.
  • A333 Grade 2 / Grade 5 — ASTM A333, earlier editions: Withdrawn grades; Grades 1, 3, 4, 6, 7, 8, 9, 10 and 11 remain.
  • StE 255 / TTSt 35N — DIN 17173 (withdrawn): The German low-temperature pipe grades, replaced by EN 10216-4.

Key data for A333 Grade 6

Yield240 MPa Grade 6 — specified minimum
Tensile415 MPa
Carbon≤ 0.3 %
StandardASTM A333

Full composition, mechanical properties by thickness, heat treatment and applications for A333 Grade 6 →

Verified against ASTM A333/A333M. Last checked: October 2026.