Corten Steel (weathering)
Frequently asked questions
Can Corten Steel (weathering) be laser cut?
With some limitations: Corten Steel (weathering) can be laser cut.
Can Corten Steel (weathering) be CNC machined?
Yes: Corten Steel (weathering) can be CNC machined.
Is Corten Steel (weathering) food safe?
No, Corten Steel (weathering) is not considered food safe.
Physical properties
| Density | 7850.0–7850.0 kg/m³ |
|---|---|
| Brinell hardness | 180.0 HB |
| Tensile strength | 485.0 MPa |
| Melting point | 1450.0–1500.0 °C |
| Thermal expansion | 12.0 µm/m·K |
| Moisture absorption | Negligible |
Laser processing
Surface engraving does not produce significant fumes. In industrial cutting, iron oxide fumes and dust are produced, requiring standard extraction systems.
CO₂: Reflects the CO2 laser beam at hobby level. Not cuttable. Surface engraving is possible only by using chemical marking sprays (Cermark) before the pass.
Diode: Not workable with standard diode laser due to the surface reflectivity of the metal.
Fiber: Excellent. High-power industrial fiber lasers (kW) cut significant thicknesses (up to 10-16mm) with extreme precision using nitrogen/oxygen as assist gas.
CNC / milling processing
Machinable similarly to S355 structural steel. Requires rigid high-torque spindles, low rotational speeds, constant feed rates, and abundant liquid cutting fluid to prevent tool wear.
Post-processing
Sanding: Easy to sand or mechanically brush to clean or even out the oxide layer. Use corundum abrasive discs or dry wire brushes.
Primer: mandatory. If painted, requires specific anti-corrosion epoxy primers, although the primary use of Corten is raw exposure without protective paints.
Gluing: Bondable for non-structural or decorative purposes using two-component structural epoxy adhesives, after deep sanding and thorough degreasing with acetone.
Over time: Develops outdoors a characteristic self-protective oxide patina (orange/dull brown rust color) that stops the progression of internal corrosion. Stabilization takes about 1-3 years.
Common defects
- Rust run-off: in the early weathering stages, rain washes the surface oxide, permanently staining underlying surfaces (marble, stone, concrete)
- Strong vibration or cutter breakage during CNC milling if the machine lacks adequate structural rigidity
Safety
Recommended PPE: eye_protection, gloves_leather
Avoid inhaling fine rust or metal dust generated during grinding and dry sanding operations.
Availability and formats
Commercial formats: sheets 1.5–10mm, hollow sections, structural beams
Related materials
Sources
- EN 10025-5 — Hot rolled products of structural steels (weathering steels specifications)
- MatWeb — Corten Steel Technical Specifications
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.