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Inspection and Quality Control
Product thickness, width and surface quality are checked during this stage. Product samples are also sent to the laboratory for mechanical properties inspection and other testing. Finally, rust-preventive oil is applied to the products and they are packed for shipment.

As a final step in the hot-dip galvanize coating process is inspection for compliance with customer standards specifications. The coating thickness is the most important component in determining a galvanized coating's but coating uniformity, adherence, and appearance should also be checked .

Inspection before and after galvanizing :

Inspection before Hot Dip Galvanizing

Good quality hot dip galvanized coatings on fabricated articles are more likely to be achieved if correct fabrication techniques have been adhered to. Inspection of fabricated assemblies, castings and other components for hot dip galvanizing, should be carried out before dispatch to the galvanizer in order to ensure conformity to the design requirements according to the standards :

• Steel Grade
• Surface Finish
• Surface treatment
• Dimensions
• Tolerance
• Type of Inspection Documents

  Inspection after Hot Dip Galvanizing

Inspectors should remember that the purpose of hot dip galvanizing is to protect steel from corrosion.
The length of time that this protection can be expected to last, is called its "service life or time to first maintenance". This is defined as the time taken for the appearance on an article of 5% surface rust. The service life of a hot dip galvanized coating is directly related to the thickness of the protective zinc coating. Corrosion protection is greatest when the coating is thickest. Thus coating thickness is the single most important quality check.

• Steel Grade
• Coating Mass
• Surface Quality
• Coating Finish
• Surface Treatmen
• Dimensions
• Tolerances
• Packaging Weight
• Type of inspection Document

Coating thickness is only one inspection aspect. Other checks must include continuity, coating adhesion and appearance . Embitterment and defects, which arise from specific materials, design and fabrication, must also be considered when inspecting susceptible items.

While minimum standards must be satisfied in all these considerations, their relative importance varies according to the end use of the finished product. For example, the aesthetic appearance of hot dip galvanized steel sheets in an industrial application is less important than when a structure is destined for use in a decorative application. Understanding of the specific requirements as well as the limits to what can be achieved by hot dip galvanizing is essential for effective inspection.