Steel P420ML1
EN 1.8835, 10028-6
P420ML1 (1.8835) is a thermomechanically rolled fine-grain pressure vessel plate to EN 10028-6 that sits between P355ML and P460ML with 450 MPa yield, 560 MPa tensile, 25 % elongation and 175 HB.
Reference datasheet — P420ML1 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
P420ML1 tempers and conditions
P420ML1 is supplied in 6 conditions, soft to hard. M is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M | Maximum-thickness TMCP band, usually mill-order only with agreed toughness testing. | 390 | 520 | 24 | 163 HB | 8.6 % IACS |
M | Upper thickness band for TMCP supply; check mill capability and through-thickness toughness. | 400 | 525 | 24 | 165 HB | 8.6 % IACS |
M | Heavy plate for thick shells and heads where TMCP still gives full L1 toughness. | 415 | 535 | 25 | 168 HB | 8.6 % IACS |
M | Mid-thickness pressure-vessel plate; yield drops one step per EN 10028-5 thickness table. | 430 | 550 | 25 | 170 HB | 8.6 % IACS |
Stress relieved | Choose when the vessel will be post-weld heat treated; strength drops slightly and must be verified by simulated-PWHT testing. | 430 | 545 | 26 | 168 HB | 8.6 % IACS |
MDefault Thermomechanically controlled processed | Standard as-delivered TMCP plate in the thinnest thickness band — highest guaranteed yield strength. | 450 | 560 | 25 | 175 HB | 8.6 % IACS |
Supply forms, finishes and certifications
Ways P420ML1 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
+Z35 | TMCP plate with through-thickness (Z-quality) ductility per EN 10164 | Certification |
What is P420ML1?
P420ML1 (1.8835) is a thermomechanically rolled fine-grain pressure vessel plate to EN 10028-6 that sits between P355ML and P460ML with 450 MPa yield, 560 MPa tensile, 25 % elongation and 175 HB. L1 toughness qualifies it for sub-zero vessels, and a low carbon equivalent (CEV of 0.45 maximum) keeps thick-section welding practical; plate is supplied in M conditions to 100 mm plus SR and Z35 variants. Hot forming or normalizing above about 580 °C destroys the TMCP condition, service is capped at 400 °C and the plate has no inherent corrosion resistance. Specify P420ML2 where a stricter low-temperature toughness class is required. P420ML1 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F). P420ML1 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 52% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
What is P420ML1 used for?
- low-temperature reactors
- gas storage
- chemical process vessels
Advantages
- Tough — resists crack growth — 150 MPa·√m (136.5 ksi·√in), better than 96% of steel grades
- Readily welded — 88/100, better than 87% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
P420ML1 properties
Typical room-temperature values for P420ML1-M; bars are the position among steel grades.
Physical3
P420ML1 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F).
Mechanical16
P420ML1 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 52% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P420ML1 is rated for continuous service to 400°C (752 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
P420ML1 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 P420ML1 takes about 28 MJ of energy and emits 2.1 kg of CO₂ — less than 56% of steel grades. Typical recycled content is 25%.
Manufacturability7
P420ML1's machinability is good (55/100, better than 62% of steel grades); weldability excellent (88/100); formability good (65/100).
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. P420ML1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with P420ML1
Is P420ML1 easy to machine?
Machines like a tough HSLA plate (~60 % of AISI 1212): use rigid setups, positive-rake coated carbide, moderate speed and generous feed to avoid work-hardened, gummy chips.
Can P420ML1 be welded?
Excellent weldability at CEV ≤ 0.45 — SAW/GMAW/SMAW with low-hydrogen consumables; keep heat input within the mill's recommended window (typically ≤ ~35–50 kJ/cm) so the TMCP HAZ retains its low-temperature toughness, and avoid unnecessary PWHT.
Can P420ML1 be formed, bent or molded?
Good cold formability for rolling shells and pressing heads with generous bend radii (≈2–3 t); hot forming above ~580 °C degrades the TMCP condition and then requires re-normalising or requalification.
P420ML1 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 |
|---|---|---|
| Cladle analysis max | ≤ 0.18 | 0.1 |
| Si | ≤ 0.5 | 0.3 |
| Mn | 1 – 1.7 | 1.5 |
| PML grades typically ordered ≤0.020 | ≤ 0.03 | 0.01 |
| SML1 low-S clean steel practice | ≤ 0.02 | 0 |
| Altotal Al, grain refining | ≥ 0.02 | 0.04 |
| NbNb+Ti+V ≤ 0.22 | ≤ 0.05 | 0.03 |
| Ti | ≤ 0.05 | 0.02 |
| V | ≤ 0.2 | 0.05 |
| Niaids low-temperature toughness | ≤ 0.8 | 0.3 |
| Cr | ≤ 0.3 | 0.05 |
| Mo | ≤ 0.25 | 0.08 |
| Cu | ≤ 0.7 | 0.15 |
| N | ≤ 0.03 | 0.01 |
| Fe | balance |
What surface finishes work on P420ML1?
No natural corrosion resistance — shot-blast to Sa 2.5 and apply epoxy/PU coating, metallize or clad; galvanizing is possible but check silicon level for coating appearance.
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 P420ML1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.883510028-6
How much does P420ML1 cost?
P420ML1 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.
P420ML1 — frequently asked
What is P420ML1 used for?
P420ML1 is typically used for low-temperature reactors, gas storage and chemical process vessels. In short: 450 MPa vessel plate; weldable at CEV 0.45; mid-strength TMCP step.
What is the yield strength of P420ML1?
P420ML1 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is P420ML1 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like a tough HSLA plate (~60 % of AISI 1212): use rigid setups, positive-rake coated carbide, moderate speed and generous feed to avoid work-hardened, gummy chips.
Can P420ML1 be welded?
Yes — weldability is rated excellent (88/100). Excellent weldability at CEV ≤ 0.45 — SAW/GMAW/SMAW with low-hydrogen consumables; keep heat input within the mill's recommended window (typically ≤ ~35–50 kJ/cm) so the TMCP HAZ retains its low-temperature toughness, and avoid unnecessary PWHT.
What surface finishes work on P420ML1?
No natural corrosion resistance — shot-blast to Sa 2.5 and apply epoxy/PU coating, metallize or clad; galvanizing is possible but check silicon level for coating appearance.
Can P420ML1 be formed, bent or molded?
Good cold formability for rolling shells and pressing heads with generous bend radii (≈2–3 t); hot forming above ~580 °C degrades the TMCP condition and then requires re-normalising or requalification.
What is the maximum service temperature of P420ML1?
P420ML1 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between P420ML1-M and P420ML1 M-63-80?
M is the default condition — standard as-delivered TMCP plate in the thinnest thickness band — highest guaranteed yield strength. M-63-80: upper thickness band for TMCP supply; check mill capability and through-thickness toughness. Yield strength is 450 MPa in M versus 400 MPa in M-63-80.
How much does P420ML1 cost?
P420ML1 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
- EN 10028-5 — Flat products made of steels for pressure purposes, Part 5: Weldable fine grain steels, thermomechanically rolled — CEN (2017)
- EN 10164 — Steel products with improved deformation properties perpendicular to the surface — CEN (2018)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- TMCP pressure-vessel plate datasheets (P355M/P420M/P460M series) — European plate mills (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.