Structural Steel (S355)
Frequently asked questions
Can Structural Steel (S355) be laser cut?
With some limitations: Structural Steel (S355) can be laser cut. Adequate extraction/ventilation is required.
Can Structural Steel (S355) be CNC machined?
Yes: Structural Steel (S355) can be CNC machined.
Is Structural Steel (S355) food safe?
No, Structural Steel (S355) is not considered food safe.
Physical properties
| Density | 7850.0–7850.0 kg/m³ |
|---|---|
| Brinell hardness | 165.0 HB |
| Tensile strength | 510.0 MPa |
| Melting point | 1425.0–1540.0 °C |
| Thermal expansion | 12.0 µm/m·K |
| Moisture absorption | Negligible |
Laser processing
Generates iron and manganese oxides as fine particulate during cutting. Manganese in prolonged quantities is neurotoxic; ventilation mandatory in enclosed spaces.
CO₂: Like all steels, reflects the CO2 beam. Cutting at maker level is impossible; surface engraving requires chemical marking sprays (Cermark) with modest results.
Diode: Impossible to cut or directly mark with diode laser due to high reflectivity of the metal surface.
Fiber: Excellent with fiber laser of adequate power. Compared to S235 it requires slightly more power for equivalent thicknesses given the higher silicon and manganese content.
CNC / milling processing
Machinability similar to S235 but with higher mechanical strength. Requires more precise feed rates and more rigid machines to avoid vibrations. Like S235 it tends to form long chips: prefer steel-specific bits with chip breaker and continuous cooling.
Post-processing
Sanding: Similar to S235. Use corundum or zirconia abrasives. Higher hardness compared to S235 slightly reduces removal rate and wears abrasive sheets faster.
Primer: mandatory. Like S235, rusts quickly without protection. Apply anti-rust epoxy primer immediately after machining. Higher mechanical strength offers no protection against atmospheric corrosion.
Gluing: Bondable with two-component structural epoxy adhesives after sanding and degreasing. For structural applications always prefer welding.
Over time: No resistance to atmospheric corrosion without surface protection. Rusts at the same rate as S235. Always use in combination with primer and protective finish.
Common defects
- Rapid oxidation on cut edges as with S235, worsened by the greater exposed surface during milling
- Build-up of residual stresses in heavily machined parts without stress-relief treatment
Safety
Recommended PPE: gloves_cut_resistant, eye_protection, mask_p2
Cut edges are very sharp. Cut-resistant gloves mandatory. In CNC machining, extract chips to prevent dangerous accumulations. Watch for manganese fumes in non-ventilated environments.
Availability and formats
Commercial formats: bars, sheets, HEA/HEB/IPE beams, sections, Hardox sheets (high-hardness variants)
Related materials
Sources
- EN 10025-2 — Prodotti laminati a caldo di acciai per impieghi strutturali (S355)
- MatWeb — S355 Steel Datasheet
Information on compatibility, processing parameters and safety is purely indicative. MakerSpecs accepts no liability for damage to persons or property arising from the use of this data. Always check the safety rules and the manufacturer's official manuals before carrying out any processing.