Five coating systems, one supply chain: hot-dip +Z, Galvalume +AZ, Magnelis +ZM, AlSi +AS and electro +ZE — 34 grades from DC51D+Z and HC180YD+Z to SECC, slit, leveled and laser-welded in Shanghai.
A "galvanized sheet" inquiry is incomplete until the service environment is named. Here is how the five systems divide the work.
+Z hot-dip galvanized is the default: a zinc layer (typical classes Z100–Z275, g/m² total both sides) that corrodes sacrificially and protects cut edges. It runs from HVAC ducts and roofing profiles to automotive BIW parts. +AZ Galvalume swaps in a 55% Al-Zn layer — better heat reflectance and long-term atmospheric life, which is why roofs, gutters and cladding are specified +AZ. +ZM Magnelis adds a small magnesium addition that makes the zinc layer self-healing at scratches and cut edges — the fastest-growing choice for solar mounting and fencing, where guillotine cuts are unavoidable.
+AS is the odd one out in this family: an AlSi layer that is not a corrosion coating at all, but the furnace protection for press hardening steel blanks. It lives in this catalogue because the same coated lines produce it. +ZE electrogalvanized is the thin, smooth, uniform option — 5–20 µm per side typical — for painted panels, electronics and appliance parts where surface class beats coating thickness.
The numbers that anchor this page: 28 structural and forming grades on the hot-dip side (DC51D+AZ, DC54D+Z, S350GD+Z, S550GD+ZM, HC180YD+Z…) plus 6 electrogalvanized grades (SECC, SECCN5, DC01+ZE, DC04+ZE, DC06+ZE, DC01+ZEUP), a 0.4–8 mm thickness window, and a realised price band of CNY 3,620–5,860 per tonne across the 335-SKU coated range.
Hot-dip zinc is thick (Z100–Z275 g/m²), sacrificial and cheap per gram of protection, but the spangle and surface can show through paint. Electro +ZE is thin (5–20 µm), mirror-smooth and uniform — right for painted electronics and appliance exteriors where the coating is secondary to appearance.
Choose +ZE for painted surfaces and electronics; +Z for real corrosion duty.+AZ wins on heat, UV and long atmospheric life at a mature price. +ZM costs a little more but self-heals at cut edges and scratches — decisive when the part is guillotined, drilled or punched after coating. Solar rails and fencing have moved to +ZM; roof sheets largely stay +AZ.
Choose +ZM when cut edges are exposed; +AZ for hot roofs and budget.Bare cold rolled strip is cheaper and welds/paints in the simplest possible route, but it corrodes the moment humidity arrives. Coated sheet pushes the corrosion warranty onto the material instead of the paint shop. If the part lives indoors and is painted, bare may be right; anything else, coat it.
Choose coated when the environment, not the forming, is the risk.Coating classes and thickness windows indicative; confirm the class against your standard at RFQ.
| Grade | Coating | Standard | Typical application | Delivery |
|---|---|---|---|---|
| DX51D+Z | +Z hot-dip zinc | EN 10346 | Roofing profiles, HVAC duct, general forming | Coil / sheet, Z100–Z275 |
| DC51D+Z | +Z hot-dip zinc | EN 10346 | Formed panels, door skins, cabinets | Coil / sheet |
| S350GD+Z | +Z hot-dip zinc | EN 10346 | Structural profiles, purlins, framing | Coil / sheet |
| S350GD+AZ | +AZ Galvalume | EN 10346 | Roofing, cladding, gutters | Coil / sheet, AZ150 typ. |
| S550GD+ZM | +ZM Magnelis | EN 10346 | Solar mounting rails, fencing, trays | Coil / sheet, ZM310 typ. |
| HC180YD+Z | +Z hot-dip zinc | EN 10346 | Automotive BIW, bake-hardening parts | Coil |
| DC56D+Z | +Z hot-dip zinc | EN 10346 | Deep drawn coated parts | Coil |
| DC54D+AS | +AS AlSi | EN 10346 | Hot-stamping pre-coated blanks | Coil / sheet |
| SECC | +ZE electro | JIS G3313 | Electronics, electrical cabinets | Coil / sheet |
| DC01+ZE | +ZE electro | EN 10152 | Appliance parts, painted panels | Coil / sheet |
All 34 grades, coating classes and gauge bands confirmed per coil on the Mill Test Certificate.
Typical / indicative values — the delivered heat and coating class are confirmed on the MTC.
| System | Layer | Typical coating weight | Edge behavior | Where it wins |
|---|---|---|---|---|
| +Z hot-dip zinc | Pure Zn | Z100 / Z140 / Z275 g/m² | Sacrificial, protects cuts | General forming, BIW, duct |
| +AZ Galvalume | 55% Al-Zn | AZ150 typ. | Moderate cut protection | Roofs, cladding, heat exposure |
| +ZM Magnelis | Zn-Mg-Al | ZM310 typ. | Self-healing at cut edges | Solar, fencing, punched parts |
| +AS AlSi | Al-Si | AS150 class typ. | Not a corrosion layer | Hot stamping pre-coating |
| +ZE electro | Pure Zn (thin) | 5–20 µm per side | Thin — edge protection limited | Paint finish, electronics |
| Element % | DX51D+Z | S350GD+Z | SECC | HC180YD+Z |
|---|---|---|---|---|
| Carbon (C) | ≤ 0.12 | ≤ 0.20 | ≤ 0.12 | ≤ 0.01 (IF) |
| Manganese (Mn) | ≤ 0.60 | ≤ 1.70 | ≤ 0.50 | ≤ 0.70 |
| Phosphorus (P) | ≤ 0.10 | ≤ 0.10 | ≤ 0.040 | ≤ 0.06 |
| Sulfur (S) | ≤ 0.045 | ≤ 0.045 | ≤ 0.040 | ≤ 0.03 |
Indicative reference values only. Chemistry and coating weight confirmed on the Mill Test Certificate of the delivered coil.
The test: a 0.45–0.60 mm roll-formed sheet that must survive decades of sun, rain and thermal cycling with no red rust on the profile edges. Our answer: S350GD+AZ, AZ150 class, slit to profile width with burr managed so the roll former stays clean.
The test: a punched and drilled structural rail, cut edges fully exposed, load-bearing in a coastal installation. Our answer: S550GD+ZM, ZM310 class — the magnesium layer is what keeps the punch holes from bleeding rust.
The test: a 1.0–1.5 mm panel that is punched, bent and powder coated, where any surface defect shows through the paint. Our answer: SECC electro, with controlled surface class and flatness for a stable paint shop result.
The test: a deep drawn, spot-welded panel with a 10-year corrosion warranty. Our answer: HC180YD+Z (bake-hardening) or DC56D+Z for deeper draws, coil delivered with coating class and weldability data on the MTC.
The test: cheap, formable, weldable sheet that survives condensation and humid air in service. Our answer: DX51D+Z, Z100–Z140 class, cut to duct sizes — the volume product where consistency, not exotic chemistry, matters.
Coated material needs different handling than bare steel — the coating is the product, and the line has to protect it.
Coils slit to profile width or leveled and cut to sheet with burr and edge condition controlled so the coating is not damaged at the cut line.
Different gauges or coating classes joined into one blank before forming — our in-house 激光拼焊 service for automotive BIW and structural blanks.
Coating weight and surface class checked per coil; passivation and oiling status documented so the material arrives exactly as the paint shop expects.
Coil edges protected and crates designed for coated product — see the galvanized vs Galvalume guide before you lock the coating.
Substitution must be confirmed against your governing standard and coating class.
| EN grade | JIS / GB family | Coating class | Notes |
|---|---|---|---|
| DX51D+Z | SGCC (JIS G3302) · DX51D-type GB/T 2518 | Z100–Z275 | General forming workhorse |
| DC51D+Z | SGCD1 (JIS) · DC51D+Z (GB/T 2518) | Z100–Z180 | Forming tier above DX51D |
| S350GD+Z | SGC440 (JIS) · S350GD+Z (GB/T 2518) | Z140–Z275 | Structural forming tier |
| S350GD+AZ | GL-type (55% Al-Zn) · S350GD+AZ (GB/T 14978) | AZ150 typ. | Roofing standard |
| S550GD+ZM | Zn-Mg class · S550GD+ZM (GB/T 2518) | ZM310 typ. | Self-healing edge class |
| SECC | DC01+ZE · SECC (GB/T 15675) | 5–20 µm | Electro tier; SECCN5 for Ni-flash |
| HC180YD+Z | — (EN bake-hardening) | Z100–Z140 | Automotive BIW tier |
All cross-standard equivalences indicative; confirm chemistry, coating class and tolerance against the governing specification.
The +AS coating lives here in its real job — protecting 22MnB5 blanks through the hot stamping furnace.
Browse press hardening steel →
The bare substrate behind every coating — when the part is painted indoors instead.
Browse cold rolled strip →
Coated and uncoated high-strength grades for automotive body structure at 780–1180 MPa.
Browse the high-strength range →
Precision blanking counterpart where the shear face, not the environment, is the deciding factor.
Browse fine blanking steel →These grade families share material, processing or application territory with the topic on this page.
SPHC / Q235 / Q345 scale-free coils with oil coating, cost-effective for structural and tube applications.
DP / TRIP / HSLA grades (HC180YD, HC260LA, DP590) combining strength with formability for lightweighting.
Send coating + grade, gauge × width, coating class, tonnage and destination port. Our engineers reply within one working day — processing services and application guidance included.