Steel X80
ASTM API 5L X80 · GB L555
X80 is a very high strength TMCP micro-alloyed line pipe steel to API 5L X80 (L555), supplied in M, Q, MS/MO and induction-bend (IB) conditions.
Reference datasheet — X80 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the M condition
X80 tempers and conditions
X80 is supplied in 4 conditions, soft to hard. M is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
MDefault Thermomechanically controlled processed | Standard PSL2 delivery condition for UOE/JCOE/HFW/spiral line pipe and the pipeline plate/coil it is made from — pick this for onshore high-pressure gas transmission. | 600 | 690 | 22 | 18 HRC | 8.6 % IACS |
TMCP, offshore service | Offshore/submarine line pipe: tighter dimensional, geometry and toughness (DWTT/CVN) requirements per API 5L Annex J for laying and collapse resistance. | 610 | 700 | 22 | 214 HB | 8.6 % IACS |
Induction bend, quenched and tempered after bending | Hot induction bends made from X80 pipe and re-heat-treated to restore properties per ISO 15590-1 / DNV; specify when field bends are impractical. | 610 | 700 | 20 | 21 HRC | 8.6 % IACS |
Quenched and tempered | Used for heavy-wall seamless pipe, risers and fittings where TMCP rolling cannot reach the required thickness; higher hardness, slightly lower toughness margin. | 620 | 720 | 20 | 22 HRC | 8.6 % IACS |
Supply forms, finishes and certifications
Ways X80 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
MS | TMCP, sour service | Coating |
What is X80?
X80 is a very high strength TMCP micro-alloyed line pipe steel to API 5L X80 (L555), supplied in M, Q, MS/MO and induction-bend (IB) conditions. Its 600 MPa yield and 690 MPa tensile let designers cut wall thickness on high-pressure long-distance gas lines, and it is produced mainly as large-diameter longitudinal-seam and spiral welded pipe. Elongation drops to 22 % and weldability is more procedure-sensitive than X65/X70, so heat input and consumable strength must be controlled; heating above about 600 °C erases the TMCP strength. Use X70 where welding and bending practice must be less tightly controlled. X80 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). X80 has a yield strength of 600 MPa (87 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 77% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi).
What is X80 used for?
- high-pressure gas transmission
- West-East pipeline projects
- large diameter pipe
Advantages
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 100% of steel grades
- High strength — 600 MPa (87 ksi), better than 77% of steel grades
- Readily welded — 75/100, better than 76% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
X80 properties
Typical room-temperature values for X80-M; bars are the position among steel grades.
Physical3
X80 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical17
X80 has a yield strength of 600 MPa (87 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 77% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
X80 is rated for continuous service to 250°C (482 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
X80 conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of X80 takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 20%.
Manufacturability7
X80's machinability is fair (45/100, worse than 65% of steel grades); weldability very good (75/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. X80 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with X80
Is X80 easy to machine?
Machines like a tough C-Mn steel at ~50 % of 1212 — bevelling and counterboring need rigid setups, positive-rake carbide and generous coolant to avoid work-hardened, gummy chips.
Can X80 be welded?
Excellent weldability at CEIIW ≤0.43 / Pcm ≤0.25 with low-hydrogen consumables (GMAW-P/mechanized root, FCAW/SAW fill); control heat input (typically 0.5–2.0 kJ/mm) to limit HAZ softening and keep matching or slightly overmatching weld strength.
Can X80 be formed, bent or molded?
Cold formed by UOE/JCOE or spiral rolling followed by cold expansion (~1 %); allow for pronounced Bauschinger effect and springback, and avoid re-forming or heating above ~600 °C which erases the TMCP strength.
X80 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CPSL2 welded pipe, t ≤ 25 mm; TMCP steels typically 0.04–0.08 | ≤ 0.12 | 0.06 |
| Si | ≤ 0.45 | 0.25 |
| Mn | ≤ 1.85 | 1.75 |
| P | ≤ 0.03 | 0.01 |
| S≤0.002 typical for MS sour-service | ≤ 0.02 | 0 |
| NbNb+V+Ti ≤ 0.15 total | ≤ 0.11 | 0.06 |
| V | ≤ 0.1 | 0.02 |
| Ti | ≤ 0.06 | 0.02 |
| Cu | ≤ 0.5 | 0.2 |
| Ni | ≤ 1 | 0.25 |
| Cr | ≤ 0.5 | 0.15 |
| Mo | ≤ 0.5 | 0.2 |
| B | ≤ 5×10⁻⁴ | 2×10⁻⁴ |
| AlAl/N ≥ 2:1 typical | ≤ 0.06 | 0.03 |
| N | ≤ 0.01 | 0.01 |
| FeCEIIW ≤ 0.43 %, Pcm ≤ 0.25 % | balance |
What surface finishes work on X80?
Shot blast to Sa 2½ then FBE, 3-layer PE/PP or liquid epoxy coating; external corrosion control always combines coating with cathodic protection — no anodizing, and hot-dip galvanizing is not used on line pipe.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel X80 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- API 5L X80
- GB (China)
- L555
How much does X80 cost?
X80 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
X80 — frequently asked
What is X80 used for?
X80 is typically used for high-pressure gas transmission, west-East pipeline projects and large diameter pipe. In short: highest-strength common line pipe; thinner wall, less steel; weld-procedure sensitive.
What is the yield strength of X80?
X80 has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 77% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is X80 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machines like a tough C-Mn steel at ~50 % of 1212 — bevelling and counterboring need rigid setups, positive-rake carbide and generous coolant to avoid work-hardened, gummy chips.
Can X80 be welded?
Yes — weldability is rated very good (75/100). Excellent weldability at CEIIW ≤0.43 / Pcm ≤0.25 with low-hydrogen consumables (GMAW-P/mechanized root, FCAW/SAW fill); control heat input (typically 0.5–2.0 kJ/mm) to limit HAZ softening and keep matching or slightly overmatching weld strength.
What surface finishes work on X80?
Shot blast to Sa 2½ then FBE, 3-layer PE/PP or liquid epoxy coating; external corrosion control always combines coating with cathodic protection — no anodizing, and hot-dip galvanizing is not used on line pipe.
Can X80 be formed, bent or molded?
Cold formed by UOE/JCOE or spiral rolling followed by cold expansion (~1 %); allow for pronounced Bauschinger effect and springback, and avoid re-forming or heating above ~600 °C which erases the TMCP strength.
What is the maximum service temperature of X80?
X80 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between X80-M and X80-Q?
M is the default condition — standard PSL2 delivery condition for UOE/JCOE/HFW/spiral line pipe and the pipeline plate/coil it is made from — pick this for onshore high-pressure gas transmission. Q: used for heavy-wall seamless pipe, risers and fittings where TMCP rolling cannot reach the required thickness; higher hardness, slightly lower toughness margin. Yield strength is 600 MPa in M versus 620 MPa in Q.
How much does X80 cost?
X80 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- API 5L Specification for Line Pipe, 46th ed. (PSL2 grade L555M/X80M) — American Petroleum Institute (2018)
- ISO 3183 Petroleum and natural gas industries — Steel pipe for pipeline transportation systems — ISO (2019)
- ISO 15156-2 / NACE MR0175 — Materials for use in H₂S-containing environments — ISO / AMPP (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (HSLA steels) — ASM International (1990)
- High-strength TMCP line pipe steel (X80) product literature — Baosteel / Nippon Steel / Europipe (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.