Steel S550MC
EN S550MC · GB Q550M
S550MC is a thermomechanically rolled micro-alloyed HSLA sheet grade (also designated Q550M) supplied in TM, pickled, shot-blasted and slit conditions, with 595 MPa yield, 680 MPa tensile, 16 % elongation and about 200 HB.
Reference datasheet — S550MC 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 TM condition
S550MC tempers and conditions
S550MC is supplied in 3 conditions, soft to hard. TM is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
TMDefault Thermomechanically rolled, as-delivered hot-rolled coil/sheet | Standard EN 10149-2 delivery condition for cold-formed structural parts, 1.5–16 mm. | 595 | 680 | 16 | 200 HB | — |
TM + pickled and oiled | Choose for direct press forming, laser cutting and painting where mill scale is unacceptable. | 600 | 680 | 15 | 14 HRC | 9 % IACS |
TM + skin-passed / temper rolled | Light temper pass for improved flatness and suppression of yield-point elongation on visible pressings. | 615 | 690 | 14 | 15 HRC | 9 % IACS |
Supply forms, finishes and certifications
Ways S550MC is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
TM-slit | TM slit strip / cut-to-length sheet | Surface finish |
TM+SB | TM + shot blasted | Surface finish |
What is S550MC?
S550MC is a thermomechanically rolled micro-alloyed HSLA sheet grade (also designated Q550M) supplied in TM, pickled, shot-blasted and slit conditions, with 595 MPa yield, 680 MPa tensile, 16 % elongation and about 200 HB. It is chosen for demanding lightweight welded structures that still have to be cold formed, typically from hot-rolled coil, slit strip and laser-cut blanks. Formability (score 62) and machinability (score 45) are lower than S500MC, and post-weld normalizing or hot forming above roughly 580 °C removes the thermomechanical strengthening. Step down to S500MC where more elongation or tighter bends are needed. S550MC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F). S550MC has a yield strength of 595 MPa (86.3 ksi) and a tensile strength of 680 MPa (98.6 ksi) — stronger than 76% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
What is S550MC used for?
- Crane telescopic boom sections
- High-strength vehicle chassis parts
- Trailer and semi-trailer frame members
- Roll-formed high-strength profiles
- Lifting and handling equipment arms
- Tipper and skip body reinforcements
- Agricultural implement frames
Advantages
- Readily welded — 80/100, better than 79% of steel grades
- Forms and bends easily — 62/100, better than 78% of steel grades
- High strength — 595 MPa (86.3 ksi), better than 76% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
S550MC properties
Typical room-temperature values for S550MC-TM; bars are the position among steel grades.
Physical3
S550MC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical16
S550MC has a yield strength of 595 MPa (86.3 ksi) and a tensile strength of 680 MPa (98.6 ksi) — stronger than 76% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S550MC is rated for continuous service to 350°C (662 °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
S550MC conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of S550MC takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
S550MC's machinability is fair (45/100, worse than 65% of steel grades); weldability very good (80/100); formability good (62/100).
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. S550MC is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S550MC
Is S550MC easy to machine?
Machinable with carbide at moderate speeds; the fine-grained microstructure gives stringy chips — use positive rake and chip-breaking geometry, plan for ~55 % of 1212 speeds.
Can S550MC be welded?
Excellent weldability with low CEV; use low-hydrogen consumables of matching or slightly undermatching strength, limit heat input (~1.0–1.5 kJ/mm) and avoid post-weld normalising, which destroys the TM strength.
Can S550MC be formed, bent or molded?
Designed for cold forming — typical minimum inner bend radius 1.5–2.0×t transverse to rolling direction; allow for ~15–20° springback and roll-form rather than hard-bend thick sections.
S550MC 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, EN 10149-2 | ≤ 0.12 | 0.08 |
| Si | ≤ 0.5 | 0.2 |
| Mn | ≤ 1.8 | 1.55 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.02 | 0 |
| Altotal Al, min value | ≥ 0.02 | 0.04 |
| NbNb+V+Ti ≤ 0.22 total | ≤ 0.09 | 0.05 |
| V | ≤ 0.2 | 0.03 |
| Ti | ≤ 0.15 | 0.05 |
| Mooptional, producer dependent | ≤ 0.5 | 0.02 |
| Boptional | ≤ 0.01 | 5×10⁻⁴ |
| Fe | balance |
What surface finishes work on S550MC?
Bare steel must be protected: shot-blast or pickle, then e-coat, powder coat, primer/paint or zinc plating; hot-dip galvanizing is possible but keep bath time short to avoid softening.
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 S550MC in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- GB (China)
- Q550M
How much does S550MC cost?
S550MC 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.
S550MC — frequently asked
What is S550MC used for?
S550MC is typically used for crane telescopic boom sections, high-strength vehicle chassis parts, trailer and semi-trailer frame members, roll-formed high-strength profiles, lifting and handling equipment arms and tipper and skip body reinforcements. In short: highest-yield cold-forming HSLA; weldable 595 MPa structural sheet; stronger than S500MC.
What is the yield strength of S550MC?
S550MC has a typical yield strength of 595 MPa (86.3 ksi) and a tensile strength of 680 MPa (98.6 ksi) — stronger than 76% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is S550MC easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machinable with carbide at moderate speeds; the fine-grained microstructure gives stringy chips — use positive rake and chip-breaking geometry, plan for ~55 % of 1212 speeds.
Can S550MC be welded?
Yes — weldability is rated very good (80/100). Excellent weldability with low CEV; use low-hydrogen consumables of matching or slightly undermatching strength, limit heat input (~1.0–1.5 kJ/mm) and avoid post-weld normalising, which destroys the TM strength.
What surface finishes work on S550MC?
Bare steel must be protected: shot-blast or pickle, then e-coat, powder coat, primer/paint or zinc plating; hot-dip galvanizing is possible but keep bath time short to avoid softening.
Can S550MC be formed, bent or molded?
Designed for cold forming — typical minimum inner bend radius 1.5–2.0×t transverse to rolling direction; allow for ~15–20° springback and roll-form rather than hard-bend thick sections.
What is the maximum service temperature of S550MC?
S550MC is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does S550MC cost?
S550MC 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 10149-2 Hot-rolled flat products made of high yield strength steels for cold forming — Part 2: Thermomechanically rolled steels — CEN (2013)
- High-strength hot-rolled structural steel S550MC data sheets — SSAB / ArcelorMittal / voestalpine (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
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.