DX51D steel (1.0226): properties, composition, equivalents
DX51D (1.0226) is the base hot-dip galvanized sheet of EN 10346: no guaranteed yield, 270–500 MPa tensile, 22 % elongation, zinc Z100–Z600 (Z275 standard). Coating codes, forming limits, SGCC/CS/DX52D comparison.
What is DX51D?
DX51D is the everyday hot-dip galvanized steel sheet: a low-carbon cold-rolled (or hot-rolled) substrate continuously coated with zinc, specified in EN 10346 for bending and profiling. Werkstoff number 1.0226; the old DIN name St02Z is still what many buyers ask for. The designation means D (flat product for cold forming), X (rolling condition not specified — may be hot- or cold-rolled), 51 (bending quality), D (hot-dip coated), plus the coating code: +Z275 is 275 g/m² of zinc over both faces (about 20 µm per side), the European default; Z100 to Z600 exist, and +ZF (galvannealed), +AZ (55 % Al-Zn), +ZA, +ZM (zinc-magnesium, ~2× the corrosion life of Z at the same mass) are alternatives.
Mechanically, EN 10346 promises only tensile 270–500 MPa and 22 % elongation — no yield minimum. That is deliberate: DX51D is for roll forming, bending and simple pressing (ducting, profiles, trapezoidal roofing, drywall track). For drawing, the ladder runs DX52D → DX53D → DX54D → DX56D; for load-bearing profiles the structural grades S220GD–S550GD guarantee yield.
JIS SGCC, GB DX51D+Z and IS 277 are the same class; ASTM A653 CS Type B G90 is the nearest American equivalent.
DX51D chemical composition
| Element | Mass % | Note |
|---|---|---|
| C | ≤ 0.18 | |
| Si | ≤ 0.5 | |
| Mn | ≤ 1.2 | |
| P | ≤ 0.12 | |
| S | ≤ 0.045 | |
| Ti | ≤ 0.3 |
EN 10346:2015 Table 1 (DX51D). The limits are wide because DX51D is defined by formability class, not chemistry; typical coil has C 0.04–0.08, Mn 0.20–0.40.
DX51D mechanical properties
| Thickness / condition | Yield strength ReH / Rp0.2 MPa (ksi) | Tensile strength Rm MPa (ksi) | Elongation A % | Hardness |
|---|---|---|---|---|
| DX51D+Z, all thicknesses (transverse) | — (no minimum; typ. 200–320) (— (no minimum; typ. 29.0–46.4)) | 270–500 (39.2–72.5) | 22 | ≈ 55–85 HRB (typ.) |
| DX52D+Z (for comparison) | 140–300 (20.3–43.5) | 270–420 (39.2–60.9) | 26 | — |
| DX53D+Z | 140–260 (20.3–37.7) | 270–380 (39.2–55.1) | 30 | — |
| DX54D+Z | 120–220 (17.4–31.9) | 260–350 (37.7–50.8) | 36 | — |
| DX56D+Z | 120–180 (17.4–26.1) | 260–350 (37.7–50.8) | 39 | — |
EN 10346 Table 4; A80, transverse. DX51D has no guaranteed yield or r/n values — it is a bending and profiling grade. Ductility ladder: DX51D (bending) → DX52D (drawing) → DX53D (deep drawing) → DX54D (special deep) → DX56D (extra deep) → DX57D (super deep).
DX51D equivalent grades
| Grade | System | Match | Why / differences |
|---|---|---|---|
| DX51D+Z | GB/T (China) | Identical | GB/T 2518 adopted the EN designation DX51D+Z. |
| IS 277 Grade O | IS (India) | Identical | IS 277 galvanized sheet, ordinary (O) grade. |
| SGCC | JIS (Japan) | Identical | JIS G3302 SGCC: commercial galvanized, Rm ≥ 270 MPa, no yield minimum; coating Z12–Z60 (g/m² one side ×10). Z27 ≈ Z275. |
| CS Type B (A653) | ASTM / ASME | Near | ASTM A653 Commercial Steel Type B, coating G90 (≈ Z275): the US commercial galvanized sheet; no guaranteed mechanicals, C ≤ 0.15. |
| DX52D | EN (European) | Near | Next formability class with guaranteed yield 140–300 MPa — order when DX51D cracks in drawing. |
| 08kp / 08ps galvanized | GOST (Russia/CIS) | Near | GOST 14918 galvanized sheet on 08kp/08ps base, group KhP (cold forming). |
| S250GD | EN (European) | Functional | Structural galvanized grade with guaranteed 250 MPa yield (EN 10346 Table 5) for load-bearing profiles. |
| DC01 | EN (European) | Functional | The uncoated cold-rolled base; DX51D is roughly DC01 substrate plus zinc. |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check. Full cross-reference for DX51D →
Old and superseded designations
| Old name | Standard | Note |
|---|---|---|
| St02Z | DIN 17162 (withdrawn) | Still the common Turkish/German shop name; St02Z ≈ DX51D+Z. |
| FeP02G / FeP02GZ | EN 10142:1990 | Renamed DX51D in EN 10142:2000, moved to EN 10346 in 2009. |
| Z1 / Z2 | BS 2989 | British commercial galvanized qualities. |
Product forms and tolerance standards
Product forms: hot-dip galvanized coil and sheet 0.30–3.0 mm (+Z), galvannealed (+ZF), zinc-aluminium (+ZA), aluminium-zinc (+AZ), zinc-magnesium (+ZM) variants, slit strip, cut lengths, pre-painted (EN 10169) base.
Dimensional tolerances: thickness/width/flatness: EN 10143; coating mass: triple-spot test, e.g. Z275 = 275 g/m² both faces total (≈ 20 µm per face); surface: A (normal), B (improved), C (best, for painting); finish: N (normal spangle), M (minimized spangle).
Key property values
DX51D yield strength
No guaranteed minimum. Typical coil measures 200–320 MPa; if the design needs a yield value, order DX52D (140–300 MPa) or a structural S250GD/S280GD.
DX51D tensile strength
270–500 MPa (39–73 ksi) transverse.
DX51D elongation
≥ 22 % (A80, transverse); reduced by 2 points below 0.7 mm.
Zinc coating and corrosion life
Z275 ≈ 20 µm/face gives roughly 20–40 years in rural C2, 10–20 years in urban C3 and 3–8 years in coastal C4 atmospheres (ISO 9223 categories, EN ISO 14713-1 guidance). Z140 ≈ 10 µm/face; Z600 ≈ 42 µm/face. ZM120 ≈ Z275 in corrosion life at less than half the coating mass.
Physical properties
Density 7.85 g/cm³ (steel), E = 210 GPa; thickness 0.30–3.0 mm (thicker on request), width to 1800 mm. Coating mass is measured by the triple-spot test in g/m² total for both faces.
Weldability
Resistance spot welding is standard with 10–20 % higher current, electrode dressing and shorter electrode life than uncoated sheet. MAG/laser welding is possible with zinc fume extraction; ZF (galvannealed) welds more easily than Z. Welded areas lose zinc and need zinc-rich paint. Avoid welding ZM without checking fume data.
Machining, forming and heat treatment
Roll forming, bending (0.5–1 t radius), punching, shearing, slitting and laser cutting all routine; the zinc coating survives bending without flaking (test per EN 10346 T-bend). Deep drawing is limited (no r-value) — use DX53D+. Cut edges are protected by zinc's sacrificial action up to ~2 mm. Painting: pre-treat (phosphate or chromate-free conversion) or use pre-painted DX51D+Z per EN 10169.
Typical applications
- Roofing and cladding sheets (trapezoidal, corrugated), pre-painted or bare
- Drywall studs and track, ceiling profiles, light steel framing (S grades for load-bearing)
- HVAC ducting, ventilation and air-handling units
- Electrical enclosures, cable trays, junction boxes
- Appliance panels, washing-machine cabinets (as DX52D–DX54D for drawn parts)
- Automotive underbody parts (DX53D–DX56D+ZF)
- Fencing, guardrails (often post-galvanized instead), shelving, silos
DX51D compared with related grades
Frequently asked questions
What does DX51D+Z275 mean?
DX51D = flat cold-forming product, rolling condition not specified, bending quality, hot-dip coated; +Z275 = zinc coating of 275 g/m² total on both faces (≈ 20 µm each side). Additional letters give surface quality (A/B/C), spangle (N/M) and surface treatment (C chromated, O oiled, P phosphated).
What is the yield strength of DX51D?
EN 10346 does not guarantee one. Measured values are usually 200–320 MPa. If the design needs a minimum, order DX52D (140–300 MPa yield) or the structural grade S250GD (≥ 250 MPa).
DX51D or DX52D — which for pressing?
DX51D is for bending and roll forming; DX52D is the first drawing grade with a guaranteed yield window and 26 % elongation. For deep-drawn parts go to DX53D or DX54D.
Is DX51D the same as St02Z or SGCC?
Yes. St02Z was the DIN 17162 name, FeP02G the 1990 EN name, and DX51D the current EN 10346 name. JIS SGCC is the Japanese commercial galvanized equivalent.
How long does Z275 galvanizing last?
Depends on the atmosphere: 20–40 years in rural areas, 10–20 in urban/industrial, 3–8 near the coast. Zinc-magnesium (ZM) coatings double that life at equal mass; pre-painting extends it further.
Related grades
Verified against EN 10346:2015; EN 10346:2015 Tables 1, 4 and coating tables; EN 10143:2006 (tolerances); EN ISO 14713-1 (corrosion categories). Last checked: September 2026.