DC01 vs DX51D: differences explained
DC01 vs DX51D: DC01 is uncoated cold-rolled sheet (EN 10130, yield 140–280 MPa, 28 % elongation); DX51D is hot-dip galvanized bending-quality sheet (EN 10346, no yield minimum, 22 %). Same steel, coated or not — table, coating codes and which to buy.
Overview
DC01 and DX51D are, at the substrate level, close to the same low-carbon cold-rolled steel; the practical difference is that DX51D leaves the mill with a hot-dip zinc (or ZM/AZ) coating applied on a continuous line, while DC01 is bare and would be galvanized or painted after fabrication. Because the galvanizing line also anneals the strip, EN 10346 writes DX51D's mechanical guarantees differently — no yield minimum, 22 % elongation, tensile 270–500 MPa — versus DC01's 140–280 MPa yield window and 28 % elongation under EN 10130.
The buying decision is therefore about corrosion protection and process: parts that must not rust, will not be painted immediately, or are roll-formed into building products are DX51D+Z (or +ZM); parts that are welded heavily, painted or powder-coated indoors, or need the best drawability at the lowest price are DC01. Cut-edge protection, weld fume and the availability of drawing qualities (DX52D–DX56D vs DC03–DC06) are the details that decide the rest.
DC01 vs DX51D side by side
| Property | DC01 | DX51D |
|---|---|---|
| Standard | EN 10130 (cold-rolled for cold forming) | EN 10346 (hot-dip coated for cold forming) |
| Material number | 1.0330 | 1.0226 |
| Old name | St12 (DIN 1623) | St02Z (DIN 17162) |
| Coating | none (or +ZE electro-zinc 2.5–7.5 µm per EN 10152) | +Z (zinc), +ZF, +ZA, +AZ, +ZM — e.g. Z275 = 275 g/m² both faces ≈ 20 µm/face |
| Substrate | cold-rolled, skin-passed, annealed | cold-rolled (or hot-rolled) and annealed on the coating line |
| Thickness | 0.35–3.0 mm | 0.30–3.0 mm (thicker on request) |
| Yield strength | 140–280 MPa (window) | not specified (typ. 200–320) |
| Tensile strength | 270–410 MPa | 270–500 MPa |
| Elongation A80 | ≥ 28 % | ≥ 22 % |
| Carbon max | 0.12 % | 0.18 % |
| Drawing qualities in the family | DC03 / DC04 / DC05 / DC06 | DX52D / DX53D / DX54D / DX56D / DX57D |
| Structural qualities in the family | — (bright bar S235JRC; EN 10346 for coated) | S220GD … S550GD (guaranteed yield) |
| Surface | quality A/B; finish b/g/m/r; oiled | quality A/B/C; spangle N/M; passivated C, oiled O, phosphated P |
| Corrosion protection as delivered | none (rusts in days if unprotected) | Z275: 10–40 years depending on atmosphere; ZM ≈ 2× at equal mass |
| Cut-edge protection | none | zinc sacrificial protection up to ~2 mm |
| Spot welding | ideal | good; +10–20 % current, electrode wear |
| Arc/laser welding | clean | zinc fume, porosity risk; extraction needed; zinc lost at weld |
| Painting | after phosphating / primer | after conversion coating; or pre-painted (EN 10169) |
| Bending | 0 t radius possible | 0.5–1 t; coating holds (T-bend test) |
| Price (2026, coil) | 1.00 | ≈ 1.15–1.25 (Z275) |
| Typical use | enclosures, appliances, furniture, painted panels | roofing, cladding, ducting, drywall profiles, cable trays, cabinets |
Which should you choose?
DX51D+Z whenever the part will meet moisture and will not be fully painted: roofing and cladding, ventilation ducts, drywall track, cable trays, outdoor cabinets, agricultural and storage equipment. The coating is cheaper and more uniform than post-galvanizing, and cut edges are protected up to about 2 mm. Use +ZM for coastal or agricultural atmospheres, DX52D–DX54D for pressed parts.
DC01 for parts that are welded extensively, e-coated/powder-coated indoors, drawn deeply (DC04+), or where a bright, paint-ready bare surface is needed at the lowest price: appliance housings, office furniture, electrical enclosures, automotive interior brackets. Add +ZE if a light zinc layer under paint is wanted.
Do not treat them as interchangeable: DX51D has no yield guarantee (order DX52D or an S-grade if the design needs one), and welding DX51D without fume extraction is a health issue as well as a quality one.
- Indoor enclosures, appliance and furniture panels
- Heavily welded assemblies (spot, MAG, laser)
- Deep-drawn parts (as DC03–DC06)
- Powder-coated or e-coated parts
- Electro-galvanized finish under paint (+ZE)
- Lowest material price
- Roofing, cladding, trapezoidal and corrugated sheet
- HVAC ducting, air-handling units
- Drywall studs and track, ceiling profiles, light framing (S-grades)
- Cable trays, junction boxes, outdoor cabinets
- Pre-painted products (EN 10169 base)
- Any part exposed to moisture without full painting
Frequently asked questions
What is the difference between DC01 and DX51D?
DC01 (EN 10130) is bare cold-rolled sheet for forming; DX51D (EN 10346) is the same class of steel supplied hot-dip galvanized (or with ZM/AZ coating) from a continuous line. DC01 has a yield window of 140–280 MPa and 28 % elongation; DX51D has no yield minimum and 22 % elongation. The choice is about corrosion protection and downstream process.
Is DX51D just galvanized DC01?
Practically yes — the substrate is a low-carbon cold-rolled (sometimes hot-rolled) steel of DC01 type, annealed and zinc-coated in one pass. The standards and guarantees differ because the coating line changes the mechanical properties and adds the coating specification.
Which is stronger, DC01 or DX51D?
Neither is guaranteed stronger: DC01 must be 140–280 MPa yield, DX51D has no yield requirement (typically 200–320 MPa) and a wider tensile range (270–500 MPa). If strength matters, order DX52D (140–300 MPa) or the structural galvanized grades S250GD–S350GD.
Can I weld DX51D?
Yes: resistance spot welding is standard with slightly higher current; MAG and laser welding need zinc-fume extraction and produce some porosity. The zinc burns off around the weld and must be repaired with zinc-rich paint. DC01 welds cleaner.
Can I galvanize DC01 after fabrication instead of using DX51D?
Yes (batch hot-dip galvanizing, EN ISO 1461) — typical for welded frames and thick parts. It gives a thicker (50–85 µm), less uniform coating and can distort thin sheet; for sheet products DX51D from the coil is cheaper and flatter.
What are DC01 and DX51D called in old DIN and JIS?
DC01 = St12 (DIN 1623) = SPCC (JIS G3141); DX51D+Z = St02Z (DIN 17162) = SGCC (JIS G3302).
Related comparisons
Verified against EN 10130:2006 and EN 10346:2015. Last checked: September 2026.