Selection summary
Overview
DX51D+Z is an EN 10346 designation for continuously hot-dip zinc-coated low-carbon flat product intended for cold forming. DX51D identifies the substrate/forming designation and +Z identifies zinc coating, but neither defines coating mass, surface quality, finish, treatment, thickness, tolerance, oiling, passivation, spangle or final forming performance without the remaining order details.
This page separates standard-oriented limits from typical reference data. Purchase acceptance comes from the ordered specification and certified material test report.
Names and systems
Identity & standards
Similar designations across ASTM, EN, JIS, and other systems are not automatically interchangeable. Product form and ordered standard control chemistry, properties, dimensions, condition, and testing.
Reference chemistry
Composition
| Element | Reference range | Why it matters |
|---|---|---|
| Low-carbon steel substrate | EN 10346 product-controlled | Cold-forming capability |
| Zinc coating | Separate +Z coating-mass designation | Sacrificial corrosion protection |
| Surface treatment | Ordered separately | Storage, forming and paint compatibility |
Concise grade-family reference only. Confirm every element limit against the current standard for the exact product ordered.
Condition matters
Reference properties
Part performance depends on thickness, coating, tooling and ordered mechanical values.
DX51D+Z without the coating number is incomplete.
Clarify whether reported thickness includes coating and the measurement method.
Environment first
Corrosion behavior
Zinc coating provides sacrificial protection, but durability depends on coating mass, atmosphere, cut edges, forming damage and maintenance.
Continuous sheet coating does not automatically protect later welds, cut edges or enclosed crevices.
Temperature, concentration, deposits, crevices, stress, surface finish, cleaning, and fabrication quality can change service performance.
Service limits
Temperature & service
Elevated temperature can discolor, oxidize or change zinc-coating behavior and must be reviewed.
Delivery condition
Heat treatment & condition
The product is continuously hot-dip coated on a coil line with substrate and coating controls defined by EN 10346.
Post-fabrication heating, welding and coating cure can damage treatment or coating and require qualification.
Process route
Fabrication
Bending, roll forming, stamping and lock forming depend on gauge, coating, surface, lubrication and tooling radius.
Welding creates fumes and coating loss; control ventilation, procedure and repair coating.
Magnetic response: Ferromagnetic steel substrate.
Decision boundaries
Comparisons & substitution
DX51D+Z and JIS SGCC are products of different standards and are not automatic equivalents.
ASTM A653 CS designations use a different ordering system for substrate class, coating and units.
Where it is used
Applications
Ordering scope
Product forms & standards
Coil, slit coil and cut lengths under EN 10346 with EN 10143 tolerances where ordered.
Coating mass, surface quality, finish, passivation, oiling and protection film specified separately.
Decision support
Selection guidance
Choose this grade when
- A cold-formed galvanized flat product under the EN system is required.
- Coating, surface, tolerance and forming route can be fully specified.
Review another grade when
- Structural yield strength, deep drawing, exposed automotive surface or aggressive corrosion requires another designation.
- The drawing calls for SGCC or ASTM A653 without approved cross-standard conversion.
Before ordering
Procurement checklist
State EN 10346 edition, DX51D+Z and the complete coating-mass designation.
State base thickness or coated thickness, width, tolerance, surface quality, finish, passivation, oiling and spangle.
State forming route, paint compatibility, inspection, certificate, coil geometry, packing and destination.
Traceable evidence