Grade Designations Explained
DX51D is a hot-dip galvanized low-carbon steel grade under EN 10346, primarily used for cold-forming applications. Its steel grade serial number is 51 and the base material is low-carbon steel. DX51D is commonly compared with SGCC under JIS G3302; both are zinc-coated coils for general forming, and substitution should always be verified against the full specification of the relevant standard.
Higher Formability Grades: DX53D
Coating Designations: Z200 and AZ150
| Designation | Coating type | Requirement |
|---|---|---|
| Z200 | Hot-dip zinc, continuous process | Minimum 200 g/m2 total both surfaces, triple-spot test per EN 10346 |
| AZ150 | Aluminum-zinc, 55% Al, 1.6% Si, 43.4% Zn | Minimum 150 g/m2 total both surfaces per EN 10346; equal to 0.50 oz/ft2 total both sides in ASTM A792 |
Chemistry of Alu-Zinc Coatings
AZ coatings are composed of approximately 55% aluminum, 1.6% silicon and 43.4% zinc. This composition offers superior resistance to heat and corrosion combined with high thermal reflectivity and conductivity, which makes AZ150 a common choice for roofing, wall cladding and heat-reflective building envelopes.
What to Verify When Buying Wholesale
Wholesale buyers should verify the mill test certificate against the ordered standard, whether EN 10346, JIS G3302 or ASTM A653, confirm the coating mass by the triple-spot test, check surface quality and spangle type, and agree on sea-worthy packaging. For alu-zinc products, confirm the AZ designation and its ASTM A792 equivalent where required by the project specification.
Frequently Asked Questions
What is DX51D material grade? DX51D is a hot-dip galvanized low-carbon steel grade under EN 10346 used mainly for cold-forming applications.
What is DX51D equivalent to? DX51D is a European standard grade commonly compared with SGCC under JIS G3302; confirm chemistry, coating and mechanical requirements before substitution.
What does AZ150 mean? Z150 means that, in the triple-spot test under EN 10346, the minimum total coating mass on both surfaces of the aluminum-zinc coating is 150 g/m2, equivalent to 0.50 oz/ft2 total both sides in ASTM A792.
What is DX51D Z200 material? It is galvanized steel coil produced by a continuous hot-dip galvanizing process with a Z200 zinc coating designation of 200 g/m2 total both surfaces.
What is DX53D equivalent to? DX53D corresponds to steel number 1.0355 in EN 10346:2009 and 1.0952 in EN 10346:2015.
Which coating is better for heat reflection: Z200 or AZ150? Z150 has higher thermal reflectivity because of its aluminum content, making it the better choice for heat-reflective building applications.