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Technical Info Sheet #8

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IDENTIFICATION OF PARTS TO BE HOT-DIP GALVANIZED

What markings do people use on objects to galvanize?

Galvanizing plants handle large batches of steel composed of many components and originating from many customers on a daily basis. For galvanizing and planning reasons, large batches are often split up and material from different customers is sometimes handled together. Galvanizing plants use temporary labels to mark batches. When markings are useful even after galvanizing (for assembly, for example) the fabricator will opt for marking methods of a permanent nature. If not then markings of a temporary nature will suffice.

IDENTIFICATION OF PARTS TO BE HOT-DIP GALVANIZED
IDENTIFICATION OF PARTS TO BE HOT-DIP GALVANIZED

TRADEMARK METHODS OF A PERMANENT NATURE

One of the following three options is usually chosen:

  • Deep striking
    This striking is done directly on the black (not galvanized) steel part. It is preferable to choose a central, easily visible and accessible location. The impact letters or codes should be sufficiently high (10-15mm) and deep (≥1mm) to remain legible even after galvanization.
  • Welding of marks or codes (see Fig. 1)
    This is also done directly on the black steel. The codes are formed by a weld in the form of numbers or letters. In this case, the fabricator must take great care to completely remove any welding spray applied to ensure proper zinc coating formation on site.
  • Welding of deeply penetrated bare steel brand plates (see Fig. 2)
    Again, the welding spray should be thoroughly removed. Make sure there is enough space between the plate and surface to allow for proper zinc coating.
Figure 1: Soldering marks or codes
Figure 1: Soldering marks or codes
Figure 2 Welding of deeply indented bright steel mark plates
Figure 2 Welding of deeply indented bright steel mark plates

TRADEMARK METHODS OF A TEMPORARY NATURE

Usually one of the four following options is chosen here:

  • Attaching marking plates (“labels”) with steel wire (see Fig. 3)
    The marks on these marking plates can either be stamped deep or welded on. Fixing them with wire will be done sufficiently loosely so that plates do not stick to the zinc coating during galvanizing and so that the entire inside of the tapping hole can come into good contact with the molten zinc.
  • Markings with appropriate pins or chalk
    The structural engineer shall use only the pins or chalk agreed upon with the galvanizer.
  • Attaching acid- and heat-resistant tags (see Fig. 4)
    This type of label (commonly called tag) often consists of a chip or label with QR or bar code that is still visible or registerable after galvanizing. Often for administrative and logistical handling of orders in the galvanizing plant.
  • Markings with colored labels
    Often galvanizing plants use colored labels to make certain customer requirements visible to production personnel. An example might be an internally agreed color that indicates that the galvanized material will be powder coated afterwards. It is then clear to the employees on the galvanizing line that
    the materials then go to the department where the materials are made ready for coating. It is also possible to use a color, for example, to indicate whether any post-treatment will take place at the galvanizing plant location such as pre-assembly, wire cutting, etc.
Figure 3: Attaching brand tags ("labels") with steel wire

EN ISO 1461
Coatings applied by hot-dip galvanizing to iron and steel objects – Specifications and test methods.

EN ISO 14713 part 1
Zinc coatings – Guidelines and recommendations for the protection of iron and steel in structures against corrosion – Part 1: General design principles and corrosion resistance.

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