S220GD galvanized steel coil is a continuously hot-dip galvanized structural steel manufactured to the European standard EN 10346, with a guaranteed minimum yield strength of 220 MPa. It combines structural strength, good cold-forming ability and reliable corrosion protection, which makes it one of the most widely used base grades for roll-formed building profiles, roof and wall cladding systems, purlins and solar mounting components.
What Does The Grade S220GD Mean?
Like all EN 10346 structural grades, the designation of S220GD is a code that tells you exactly what the steel guarantees:
S = Structural steel
220 = Minimum yield strength: 220 MPa (guaranteed)
GD = Grade for cold forming - the steel is designed to be roll-formed, bent, stamped or profiled without losing its structural properties
+Z = Hot-dip zinc coating (other coating types available: +ZF, +ZA, +ZM, +AZ)
- Standard: EN 10346 (also covered by GB/T 2518 in the Chinese market)
- Material number: 1.0241
- Coating types: +Z (zinc), +ZF (zinc-iron alloy), +ZA (zinc-aluminium), +ZM (zinc-aluminium-magnesium), +AZ (aluminium-zinc)
- Product forms: steel coil, slit coil, cut-to-length sheet, roll-formed profile
The "+Z" family is the classic hot-dip galvanized product, while +ZM (zinc-aluminium-magnesium) is increasingly specified for aggressive outdoor environments. When the substrate is further painted, the same S220GD+Z base is also widely used for color-coated steel (PPGI) - for more details you can refer to our S220GD+Z color coated galvanized steel coil page.
S220GD Chemical Composition (EN 10346, Max. % By Mass)
| Grade | C (Carbon) | Si (Silicon) | Mn (Manganese) | P (Phosphorus) | S (Sulfur) |
|---|---|---|---|---|---|
| S220GD (1.0241) | ≤ 0.20 | ≤ 0.60 | ≤ 1.70 | ≤ 0.10 | ≤ 0.045 |
Values refer to heat (ladle) analysis according to EN 10346. The tightly controlled carbon and sulfur levels ensure stable welding and good cold-forming behavior.
S220GD Mechanical Properties
| Grade | Min. Yield Strength (MPa) | Min. Tensile Strength (MPa) | Typical Tensile Range (MPa) | Elongation A80 min. (%) |
|---|---|---|---|---|
| S220GD | ≥ 220 | ≥ 300 | 300 – 440 | ≥ 20 |
Thickness correction for elongation (per EN 10346): reduce by 2 units for 0.50 mm < t < 0.70 mm, by 4 units for 0.35 mm < t < 0.50 mm, and by 7 units for t < 0.35 mm. Values are for longitudinal test pieces.
Because the yield strength is guaranteed rather than typical, S220GD is a real "structural" grade: engineers can calculate with a certified 220 MPa yield point. Yet with a low yield-to-tensile margin and high elongation it still bends, rolls and presses like a good forming grade.
Available Coating Types
| Coating Designation | Coating Composition | Main Characteristics |
|---|---|---|
| +Z (pure zinc) | ≥ 99% Zn | Basic corrosion protection for general and outdoor building use; the most economical choice |
| +ZF (zinc-iron / galvannealed) | Zn-Fe alloy layer | Hard, weldable surface with excellent paint adhesion, usually supplied spangle-free |
| +ZA (zinc-aluminium) | ≈ 95% Zn + 5% Al | Improved corrosion resistance over pure zinc for moderate environments |
| +ZM (Zn-Al-Mg) | Zn + Al + Mg (typical 2–4% Mg) | Self-healing cut-edge protection; much longer service life in humid, salty or industrial air |
| +AZ (aluminium-zinc) | ≈ 55% Al + 43.5% Zn + 1.5% Si | Very high heat reflectivity and corrosion resistance for roof sheeting and high-temperature exposure |
Zinc Coating Mass (g/m², Total Both Sides)
For structural building applications the coating mass is usually selected between Z100 and Z600 (triple-spot test, total both sides). Here is a practical selection guide:
| Coating Class | Total Mass (g/m²) | Approx. Per Side (µm) | Typical Application |
|---|---|---|---|
| Z100 | 100 | ≈ 7 | Light indoor components, back panels, furniture parts |
| Z180 / Z200 | 180 / 200 | ≈ 13 / 14 | General roll-formed sections, cable trays, indoor structures |
| Z275 | 275 | ≈ 19 | Outdoor roofing, purlins, wall cladding - the most common structural choice |
| Z350 | 350 | ≈ 25 | Coastal areas, industrial atmospheres, agricultural buildings |
| Z450 / Z600 | 450 / 600 | ≈ 32 / 42 | Severe corrosive environments, underground or long design-life structures |
Z275 is the most frequently ordered coating for S220GD building products. A common shortcut used in the market: 275 g/m² total both sides ≈ 19 µm of zinc per side.
Available Dimensions And Surface Options
| Parameter | Available Range |
|---|---|
| Thickness | 0.30 – 3.00 mm (standard); up to 4.0 mm available on request |
| Width | 600 – 1500 mm; slit coils from 30 mm |
| Coil weight | 3 – 8 tons per coil (customized available) |
| Surface finish | Regular spangle / minimized spangle / zero spangle |
| Surface treatment | Chromated, oiled, dry, anti-fingerprint (AFP) |
| Certificate | Mill test certificate (MTC), ISO 9001, CE; SGS / BV / TUV sample testing supported |
S220GD vs DX51D vs S250GD: Which One Should You Choose?
| Property | DX51D+Z (Forming Grade) | S220GD+Z (Structural) | S250GD+Z (Structural) |
|---|---|---|---|
| Min. yield strength | Not guaranteed (typically 140 – 300) | ≥ 220 MPa guaranteed | ≥ 250 MPa guaranteed |
| Design purpose | General forming, bending, deep drawing | Light structural + forming | Structural members under higher loads |
| Formability | Highest | Good (balanced) | Moderate (slightly stiffer) |
| Typical end uses | HVAC ducts, housings, light sheeting | Purlins, roof/wall profiles, solar brackets, light frames | Heavier purlins, C/Z sections, structural frames |
Practical guidance: if your part carries a real load - a purlin, a roll-formed roof sheet spanning a long distance, a solar mounting rail or a wall stud - choose S220GD+Z (or a higher S-grade) so the structural performance is guaranteed by certificate. If the part is purely decorative or non-load-bearing, DX51D is cheaper and even easier to form. When the section is heavily loaded and stiffened, step up to S250GD and above.
Main Applications Of S220GD Galvanized Steel Coil
- Roof & wall cladding systems - corrugated sheets, trapezoidal profiles and standing-seam panels for industrial buildings, warehouses and logistics centers
- Purlins and C/Z sections - the classic cold-formed structural members of steel portal-frame buildings
- Light gauge steel framing - wall studs, floor joists and trusses for prefab and container houses
- Solar PV mounting systems - rails, brackets and strut channels where guaranteed yield strength and long outdoor life are both required
- Agricultural buildings - poultry / livestock sheds, greenhouses and grain storage cladding
- Roof drainage - gutters, downpipes and flashings profiled from coil or sheet
- Cold storage & sandwich panel systems - as the structural liner of insulated panels
FAQ
1. What does S220GD stand for?
S220GD is an EN 10346 structural steel grade: "S" = structural steel, "220" = minimum yield strength 220 MPa, "GD" = grade suitable for cold forming, "+Z" = hot-dip zinc coating. Its material number is 1.0241.
2. What is the difference between S220GD and DX51D?
DX51D does not guarantee a minimum yield strength and is optimized for forming; S220GD guarantees a 220 MPa yield point so it can be used for load-bearing, roll-formed structural parts such as purlins and roof profiles.
3. What does Z275 mean?
Z275 is the zinc coating class: 275 g/m² of zinc measured over the total surface of both sides (≈ 19 µm per side). It is the most common coating for outdoor structural S220GD products.
4. Can S220GD+Z be used for solar mounting systems?
Yes. S220GD and S250GD are standard base grades for PV mounting rails and brackets. For coastal or high-humidity projects we recommend the +ZM (Zn-Al-Mg) coating for its superior cut-edge corrosion resistance.
5. Which thickness and width ranges can you supply?
Standard supply is 0.30–3.00 mm in thickness and 600–1500 mm in width; slit coils, sheets and custom dimensions are available on request. Coil weight is normally 3–8 tons.
6. Do you provide processing and samples before ordering?
Yes. We offer OEM slitting, cut-to-length and roll forming based on your drawings. Free samples are provided (freight paid by the buyer), and a mill test certificate accompanies every order.