S350GD+ZM310 is a structural steel coil that pairs an EN 10346 substrate with guaranteed 350 MPa minimum yield strength with a 310 g/m² zinc-magnesium (Zn-Al-Mg) coating on both faces. It is the standard choice for load-bearing profiles that must survive outdoors unpainted: purlins, solar mounting rails, sandwich panel face sheets and agricultural frames.
1.What is S350GD Steel?
S350GD is the structural grade of EN 10346 (material number 1.0529). The standard fixes the following minimum values for thicknesses of 0.70 mm and above:
|
Property |
Minimum |
Note |
|
Yield strength Rp0.2 |
350 MPa |
|
|
Tensile strength Rm |
420 MPa |
|
|
Elongation A80 |
16 % |
t ≥ 0.70 mm; lower values below 0.70 mm |
Substrate chemistry is limited to C ≤ 0.20 %, Si ≤ 0.60 %, Mn ≤ 1.70 %, P ≤ 0.10 %, S ≤ 0.045 %. Because these are guaranteed, not typical, values, they can be carried straight into structural calculations, and each coil ships with an EN 10204 3.1 mill certificate as evidence.
2.Specifications Table
|
Parameter |
Range |
|
Width |
1250–1500 mm |
|
Thickness |
By enquiry, typically 0.5–3.0 mm |
|
Coil inner diameter |
508 mm or 610 mm |
|
Coating |
ZM310, 310 g/m² total both sides |
|
Surface |
A surface, matt finish, oilless |
|
Tolerances |
EN 10143 |
Wide coils in this range suit producers of sandwich panels and long-span profiles, while slitting into narrow mults is done in-house before delivery if your line needs it. Confirm thickness, inner diameter and maximum coil weight at enquiry so packaging and freight are planned correctly.
3. Processing on Your Line
Roll forming and profiling. The Zn-Al-Mg coating is harder than pure zinc (around 100–140 HV), so it resists die scoring and keeps a clean surface through long runs. A minimum bending radius of 2× sheet thickness is recommended.
Slitting and cut-to-length. Bare cut edges stay protected longer than on a zinc coating, because ZM corrosion products migrate over the exposed steel.
Welding. Spot welding works with the same settings discipline as galvanized steel; dress electrodes regularly and reprotect arc-welded seams for outdoor use.
4. Application Scenarios
Solar structures. ZM310 is the class most often specified for ground-mount PV substructures in coastal, desert-edge and agricultural sites.
Purlins and profiles. The 350 MPa substrate carries load; the coating removes the repainting cycle.
Sandwich panels and decking. Wide coil plus matt surface gives uniform panel faces without post-painting.
Farm buildings and livestock equipment. Zn-Mg resists ammonia-rich interiors that destroy plain zinc quickly.
5. Quality Control Before Shipment
Every order runs through coating-weight testing, dimensional checks and surface inspection, and is documented on an EN 10204 3.1 certificate. Third-party inspection by SGS, BV or your own inspector before loading is welcome, and we supply export packaging with moisture barriers as standard because this coil is supplied oilless.
FAQ
Q: Is the elongation value valid at all thicknesses?
A: A80 ≥ 16 % applies from 0.70 mm up; below that, EN 10346 sets lower minimums, which we confirm on the certificate.
Q: Can you supply slit strip or cut lengths from this coil?
A: Yes, slitting and cut-to-length are available before export packing.
Q: What surface protection is applied if the coil is oilless?
A: Passivation or a temporary protective film can be added on request; coils are packed with moisture barriers for sea transport.
We produce S350GD+ZM310 coil in 1250–1500 mm widths with export packaging and full mill certification. Send the RFQ checklist above through our contact page and our team will revert with price, lead time and packing details.
