Galvanized steel sheet

Z275 is the zinc coating mass of 275 g/m² in total on both sides of the sheet, which corresponds to about 20 µm per side. The higher the number, the thicker the coating and the longer the corrosion protection. The coating mass is selected according to the conditions in which the finished product will be used, so it is worth stating the intended application in the enquiry.

DX51D is a low-carbon steel intended for cold forming, including bending and profiling. The following grades of the DX series (DX52D to DX56D) offer increasing drawability, up to extra deep drawing. The suffix +Z indicates a hot-dip zinc coating; instead of Z it may be ZM (Magnelis®), ZA (Galfan®) or AZ (Aluzinc®).

DX grades are forming steels with no guaranteed minimum yield strength, where formability matters most. Grades S220GD to S550GD are structural steels with a guaranteed minimum yield strength (the number in the designation gives it in MPa), used where the product has to carry loads, for example in profiles, sections and structural components.

Yes, a zinc coating is a good base for paints and powder coatings, provided the surface is degreased and properly prepared. Sheets with a ZF (Galvannealed) or ZE (electrogalvanized) coating are particularly suitable for painted products, as they have a matt, uniform surface with good paint adhesion.

Mostly for production where corrosion resistance without painting matters: electrical enclosures and cabinets, metal furniture, fences and gates, trailer bodies and superstructures, ventilation components, building profiles and flashings. Sheet without a mill certificate and second-grade sheet are chosen by manufacturers who do not need full mill documentation and care about price and availability.

Zinc protects the steel until the coating is used up, so durability depends on the coating mass (Z100 to Z275 in the Hen-Stol range, plus ZM, ZA and AZ coatings) and on the service conditions of the product: moisture, salt, chemicals. At cut edges the zinc protects the adjacent steel electrochemically, but on thicker sheets the edges are worth sealing. A white deposit on sheet stored in damp conditions (so-called white rust) is a surface phenomenon and usually does not disqualify the material from further processing.

The first part is the steel grade (DX51D), after the plus sign the coating type and mass (Z275 = 275 g/m² of zinc on both sides in total). The following letters describe the surface: M means minimized spangle, N normal spangle, A or B the surface quality, C chemical passivation, O oiling and U an unprotected surface. In an enquiry to Hen-Stol it is enough to state the grade, coating mass and thickness; the remaining parameters are matched to the application and current stock.