Materials & grades
API 5L X70 / L485 line pipe (PSL1 and PSL2)
API 5L X70 (ISO 3183 L485) is a line pipe grade with a minimum yield strength of 485 MPa (70.3 ksi). It is supplied as PSL1 or PSL2 pipe for large-diameter, high-pressure gas and oil transmission lines. PSL2 adds a yield ceiling, tighter chemistry and mandatory impact testing; PSL2 comes only as Q (seamless or welded) or M (welded).
Names by standard
What it is called in each region
| Region | System | Designation | Standard | Match |
|---|---|---|---|---|
| USA | API 5L (PSL1 name) | X70Grade name used for PSL1 pipe. The number is the minimum yield strength in ksi, rounded (70.3 ksi = 485 MPa). | API Spec 5L, 46th edition | Same material |
| API 5L (PSL2 designation) | X70Q / X70MPSL2 names add a delivery-condition letter. Sour-service and offshore pipe add S or O, for example X70QS. | API Spec 5L, 46th edition | Same material | |
| API 5L / ISO 3183 (metric name) | L485Metric grade name; the number is the minimum yield strength in MPa. X70 and L485 are the same steel grade. | API Spec 5L, 46th edition | Same material | |
| UK | BS EN ISO 3183 | L485Q / L485MThe UK adopts the European edition of ISO 3183; grade names are the metric names with a delivery-condition letter. | BS EN ISO 3183 | Same material |
| BS EN 10208-2 (legacy) | L485MBWithdrawn; replaced by BS EN ISO 3183. Class B pipe, thermomechanical, welded. | BS EN 10208-2 | Equivalent | |
| EU | EN ISO 3183 name | L485Q / L485MCurrent European line pipe standard, the CEN adoption of ISO 3183. | EN ISO 3183 | Same material |
| EN 10208-2 name (legacy) | L485MBSuperseded by EN ISO 3183 (withdrawn around 2012). Thermomechanical, welded. Minimum yield matches; limits on yield maximum, tensile and chemistry differ from API 5L PSL2. | EN 10208-2 | Equivalent | |
| EN 10027-2 number (EN 10208-2) | 1.8977Material number of L485MB. | EN 10208-2 | Equivalent | |
| EN 10208-2 name (legacy) | L485QBSuperseded by EN ISO 3183 (withdrawn around 2012). Quenched and tempered. Minimum yield matches; limits on yield maximum, tensile and chemistry differ from API 5L PSL2. | EN 10208-2 | Equivalent | |
| EN 10027-2 number (EN 10208-2) | 1.8955Material number of L485QB. | EN 10208-2 | Equivalent | |
| India | API 5L (ordered directly) | X70Indian pipe makers and pipeline owners order and certify to API 5L or ISO 3183 directly. IS 3589 covers pipe for water and sewage, not line pipe grades; the Indian adoption of ISO 3183 is listed below. | API Spec 5L | Same material |
| IS/ISO 3183:2019 | L485Identical adoption of ISO 3183:2019 under single numbering (BIS second revision). It supersedes IS/ISO 3183:2012 and the earlier IS/ISO 3183:2007, both withdrawn; the 2007 edition amalgamated IS 1978 (line pipe) and IS 1979 (high test line pipe). | IS/ISO 3183:2019 | Equivalent | |
| Japan | API 5L / ISO 3183 (used directly) | X70 / L485Japan has no separate line pipe grade system. Mills and operators use API 5L and ISO 3183. JIS G 3454 (STPG) and G 3455 (STS) are pressure-piping standards, not equivalents. | API Spec 5L / ISO 3183 | Same material |
On equivalence
- X70 and L485 are the same grade under two naming conventions: the X number is the minimum yield strength in ksi, the L number is the same strength in MPa.
- EN ISO 3183 uses the L485 names with a delivery-condition letter. The older European standard EN 10208-2 named the class B equivalents L485MB, L485QB; it was withdrawn around 2012 and those grades are equivalents, not identical specifications (yield maximum, tensile and chemistry differ).
- Old DIN 17172 names exist for this grade, but the sources found disagree on the pairing, so none is listed here.
- India has no separate grade names for API line pipe. BIS publishes ISO 3183 unchanged as IS/ISO 3183:2019, so the L-grade names apply there; IS 1978 and IS 1979 were amalgamated into IS/ISO 3183:2007, since withdrawn and superseded. IS 3589 covers pipe for water and sewage. In practice Indian projects specify API 5L or ISO 3183.
- Japan uses API 5L and ISO 3183 directly. JIS G 3454 (STPG) and JIS G 3455 (STS) are piping standards with different grades and scope; they are not line pipe equivalents.
- Source tables disagree on small points. Older API editions converted ksi to MPa (70 ksi = 483 MPa); the 46th edition uses the rounded metric minimum (485 MPa). Some published tables still show the older figures.
Chemical composition
Composition limits, mass %
| Element | X70 / L485 PSL1, seamless, up to 25 mm wallUSA · API Spec 5L, 46th edition (PSL1) | X70 / L485 PSL1, welded, up to 25 mm wallUSA · API Spec 5L, 46th edition (PSL1) | L485Q / X70Q (seamless and welded), up to 25 mm wallUSA · API Spec 5L, 46th edition (PSL2) | L485M / X70M (welded only), up to 25 mm wallUSA · API Spec 5L, 46th edition (PSL2) |
|---|---|---|---|---|
| C | ≤0.28 | ≤0.26 | ≤0.18 | ≤0.12 |
| Si | — | — | ≤0.45 | ≤0.45 |
| Mn | ≤1.40 | ≤1.65 | ≤1.80 | ≤1.70 |
| P | ≤0.030 | ≤0.030 | ≤0.025 | ≤0.025 |
| S | ≤0.030 | ≤0.030 | ≤0.015 | ≤0.015 |
| Cr | ≤0.50 | ≤0.50 | — | ≤0.50 |
| Ni | ≤0.50 | ≤0.50 | — | ≤0.50 |
| Mo | ≤0.15 | ≤0.15 | — | ≤0.50 |
| Cu | ≤0.50 | ≤0.50 | — | ≤0.50 |
| B | — | — | — | ≤0.001 |
| Nb+V+Ti | ≤0.15 unless otherwise agreed | ≤0.15 unless otherwise agreed | ≤0.15 | ≤0.15 |
| CE | not specified | not specified | — | — |
| CEIIW | — | — | ≤0.43 (C >0.12) | ≤0.43 (C >0.12) |
| CEPcm | — | — | ≤0.25 (C ≤0.12) | ≤0.25 (C ≤0.12) |
Mechanical properties
Strength and hardness
| Condition | Tensile strength | Yield strength | Elongation | Hardness |
|---|---|---|---|---|
| PSL1, X70 / L485, pipe bodySpecified minimums only; no maximum yield or tensile; elongation depends on size by formulaAPI Spec 5L, 46th edition; minimums confirmed for PSL2 by Mannesmann | ≥570 MPa≥82.7 ksi | ≥485 MPa≥70.3 ksi | — | — |
| PSL2, X70Q / X70M, pipe bodySpecified minimum and maximum; yield-to-tensile ratio ≤0.93; Charpy V-notch test required; elongation depends on size by formulaAPI Spec 5L, 46th edition as listed by Mannesmann (Salzgitter) | 570–760 MPa82.7–110.2 ksi | 485–635 MPa70.3–92.1 ksi | — | — |
In practice
Behaviour, heat treatment and uses
Characteristics
- Minimum yield 485 MPa (70.3 ksi) and minimum tensile 570 MPa (82.7 ksi) apply to both PSL levels; PSL2 also caps yield at 635 MPa and tensile at 760 MPa.
- PSL2 limits the yield-to-tensile ratio to 0.93, which keeps some strain-hardening capacity in the pipe.
- PSL2 requires Charpy V-notch impact testing; PSL1 does not. Minimum energy and test temperature depend on grade, size and the purchase order.
- Weldability is controlled in PSL2 by a carbon-equivalent limit: CE (IIW) ≤0.43 when carbon is above 0.12 %, CE (Pcm) ≤0.25 when carbon is 0.12 % or below. PSL1 sets no carbon-equivalent limit.
- There is no normalized PSL2 version of X70: the grade is made as Q (quenched and tempered) or M (thermomechanically rolled), with low carbon for field weldability.
- Sour-service (S) and offshore (O) variants are PSL2 only and add hardness and chemistry limits.
- The edition behind these values is the 46th (2018). API published a 47th edition in 2026 that revises chemical element ranges among other items; confirm limits against the edition on your purchase order.
Heat treatment
- Delivery condition is part of the PSL2 grade name: R as rolled, N normalized (or normalizing formed), Q quenched and tempered, M thermomechanical rolled or formed.
- PSL1 names carry no condition letter; PSL1 pipe is delivered in a condition set by the standard for the process or agreed with the buyer.
- Seamless pipe in the higher grades is usually quenched and tempered; large-diameter welded pipe in the higher grades is usually made from thermomechanically rolled plate or coil.
- Field welding procedures should be qualified for the actual carbon equivalent; preheat depends on wall thickness and CE, not on the grade name alone.
Typical uses
- Large-diameter, high-pressure gas transmission lines
- Long-distance oil pipelines
- New-build systems that trade grade for thinner wall
Pipe and tube steels
Similar grades compared
| Grade | C % | Mn % | Cr % | Ni % | Tensile, first listed condition |
|---|---|---|---|---|---|
| API 5L X70 / L485 | ≤0.28 | ≤1.40 | ≤0.50 | ≤0.50 | ≥570 MPa |
| API 5L X42 / L290 | ≤0.28 | ≤1.30 | ≤0.50 | ≤0.50 | ≥415 MPa |
| API 5L X52 / L360 | ≤0.28 | ≤1.40 | ≤0.50 | ≤0.50 | ≥460 MPa |
| API 5L X60 / L415 | ≤0.28 | ≤1.40 | ≤0.50 | ≤0.50 | ≥520 MPa |
| API 5L X65 / L450 | ≤0.28 | ≤1.40 | ≤0.50 | ≤0.50 | ≥535 MPa |
| A53 Grade B | ≤0.30 | ≤1.20 | ≤0.40 | ≤0.40 | ≥415 MPa |
| A106 Grade B | ≤0.30 | 0.29–1.06 | ≤0.40 | ≤0.40 | ≥415 MPa |
| A500 Grade B / C | ≤0.26 | ≤1.35 | — | — | ≥400 MPa |
| IS Yst 310 | ≤0.26 | ≤1.35 | — | — | ≥330 MPa |
| S355J2H | ≤0.23 | ≤1.35 | — | — | 470–630 MPa |
Composition from the US standard where one exists, otherwise the first standard listed on each grade's page. Strength conditions differ between grades; open a grade for its full table.
Questions answered
Common questions
What is the difference between X70M and X70Q?
Both are PSL2 with a 485 MPa minimum yield. X70M is thermomechanically rolled or formed, welded only, with carbon at or below 0.12 %. X70Q is quenched and tempered, seamless or welded, with carbon up to 0.18 %.
Is API 5L X70 the same as L485?
Yes. X70 is the API name from the 70 ksi minimum yield and L485 is the ISO name from the 485 MPa minimum yield. They are one grade.
Why is the maximum yield of X70 PSL2 higher than for X65?
PSL2 caps yield at a set margin above the minimum: 635 MPa for X70 against 600 MPa for X65. The tensile ceiling is 760 MPa for both.
What is the equivalent of API 5L X70 in Europe, India and Japan?
Europe: L485 with Q or M in EN ISO 3183 (the withdrawn EN 10208-2 grades were L485MB, 1.8977, and L485QB, 1.8955). India: IS/ISO 3183:2019, the identical Indian adoption of ISO 3183 (L485), and projects also order API 5L directly. Japan: no separate grade; it orders API 5L or ISO 3183 directly.
From the Corona catalog
Need a part made to this specification?
Send the drawing, the material or grade, the finish, the quantity and the delivery country. The team reviews the requirement and the manufacturing route.
Start an enquiryKeep reading
Related references
References
Sources
- API Specification 5L, 46th edition (announcement and effective date) — Edition the values on this page follow.
- API announces 47th edition of API Specification 5L (2026) — Newer edition; the standard's own tables were not available to check.
- Mannesmann (Salzgitter): L485M / X70M, API 5L PSL 2 grade data — Composition maxima, yield and tensile limits.
- Nippon Steel: Steel tube and pipe catalog (applicable specifications, sour and offshore grades) — Lists API 5L grades B to X100, ISO 3183, and QS/QO grades; lists JIS G 3454 and G 3455 as separate pressure-piping standards.
- Arvedi: steels for large diameter pipelines (API 5L and EN 10208-2) — PSL1 minimum yield and tensile strength for X42 and X52; EN 10208-2 material numbers.
- BIS: IS/ISO 3183:2007, Petroleum and natural gas industries, steel pipe for pipeline transportation systems (withdrawn) — Identical adoption of ISO 3183 that amalgamated IS 1978 and IS 1979.
- METI (Japan): list of applicable standards naming ISO 3183 (API 5L) as the line pipe standard — Lists JIS G 3454, G 3455 and G 3456 as piping standards and ISO 3183 (API 5L) separately as line pipe.
- Genorma: EN 10208-2:2009 (withdrawn) — Withdrawn; replaced by EN ISO 3183.
- Bühlmann Group: steel line pipe product table (EN 10208-2 material numbers) — EN 10208-2 grade names and material numbers.
- Tubing China: chemical composition for API 5L PSL 2 pipes — PSL2 chemical limits by grade and delivery condition; cross-checked against Mannesmann for the grades it lists.
- Tubing China: chemical composition for API 5L PSL 1 pipes — PSL1 carbon and manganese limits for seamless and welded pipe.
- ProjectMaterials: API 5L PSL1 vs PSL2 — Differences between the two product specification levels.
- Total Materia: API Grade X52 PSL 1 and PSL 2 (cross-references, API 5L 2004 values) — Older-edition values and the L 360 GA, StE 360.7 cross-references.
- Valve World Americas: API publishes 47th edition of line pipe standards — Lists the topics changed in the 47th edition, including chemical element ranges.
- API announces 47th edition of API Specification 5L (news release, 2 June 2026) — Confirms the 47th edition was published in June 2026 and lists chemical element ranges among the updated topics; gives no values.
- BIS: IS/ISO 3183:2019, Petroleum and natural gas industries, steel pipe for pipeline transportation systems (second revision) — Latest Indian adoption of ISO 3183 listed by BIS; identical under single numbering; supersedes IS/ISO 3183:2012.
- BIS: IS/ISO 3183:2012 (first revision, withdrawn, superseded by IS/ISO 3183:2019) — Shows the chain 2007, 2012, 2019.
- Krakatau POSCO: plate for pipeline, API 5L 45th edition table — Independent mill table: PSL2 yield and tensile ranges, yield-to-tensile 0.93, and M-grade chemistry.
- Salzgitter Flachstahl: hot-rolled coils for large-diameter pipes (EN 10208-2 and API 5L grade correspondence) — Independent mill table: PSL2 N and M chemistry, including X60N carbon equivalent as agreed.
- Mannesmann (Salzgitter): L485 / X70, API 5L PSL 1 grade data — PSL1 welded C 0.26 and Mn 1.65 maxima; minimum yield and tensile.
Values summarize published limits and typical data. The governing standard and the current edition control; check them before specifying.