SteelKey facts
- Hot-dip galvanizing prepares the steel by cleaning, pickling and fluxing before it goes into molten zinc.
- In the zinc bath the iron in the steel reacts with the zinc and forms a bonded coating of zinc-iron alloys.
- On a continuous line, surplus zinc is removed and the coating is cooled so that it solidifies on the steel.
- For steel wire, EN 10244-2 specifies the coating mass and ASTM A641 sets a minimum zinc mass for each class, both as zinc per square metre in g/m².
- The galvanizing is carried out by the mills in Türkiye that Reinwent sources from, not by Reinwent.
The process in one paragraph
A galvanizing line takes bare steel wire and makes it accept zinc. First the surface is cleaned, then acid removes the scale, then a flux coats the clean steel. The wire then passes through a bath of molten zinc, where the zinc and the steel react. On the way out, surplus zinc is taken off and the coating cools and sets. This guide follows those steps as neutral references describe them, then turns to what a buyer can use: how the process ends in a number on the order. For the plain definition of the product, read what galvanized wire is.
Where the process is carried out
Reinwent is a trading and sourcing company. We do not galvanize wire, and we do not run or inspect a galvanizing line. The process described here is carried out by manufacturers in Türkiye that we source from. Our part starts when you send a specification and we collect offers against it. See hot-dip galvanized wire and galvanized wire from Türkiye.
The steps, in order
1. Cleaning
The American Galvanizers Association states that proper surface preparation is critical, because zinc will not react with unclean steel. Degreasing is the first stage, and it removes dirt, oil and organic residue. Wikipedia describes the same stage as a caustic cleaning followed by a rinse. IspatGuru describes the cleaning unit of a continuous line as typically using an alkaline liquid combined with brushing, rinsing and drying.
2. Pickling
The second stage is an acid bath. The association describes it as chemical cleaning that strips mill scale and iron oxide from the steel, and Wikipedia calls it pickling in an acidic solution, again followed by a rinse.
3. Fluxing
Flux is the last piece of preparation. According to the association, it removes remaining oxides and leaves a protective layer that prevents new oxide forming before galvanizing. Wikipedia adds that the flux is often zinc ammonium chloride, that it dries on the steel, and that it helps the molten zinc wet and adhere.
IspatGuru describes pickling and fluxing for batch galvanizing, not for its continuous line, so we do not state that every wire line fluxes in the same way.
4. The molten zinc bath
Wikipedia states that the steel is dipped into the molten zinc and held there, and that the zinc alloys with the surface of the base metal to form a metallurgical bond. The association describes the result as zinc-iron intermetallic layers topped by a layer of pure zinc.
For a buyer, this means the coating is alloyed with the steel, not painted on, and it is built up in the bath, so how much zinc ends up on the wire depends on what happens in and just after it.
On a continuous line, IspatGuru says the molten coating is applied to the steel in a continuous process, and names wire next to sheet and strip among the products of galvanizing lines.
5. Wiping surplus zinc
The wire comes out of the bath carrying more zinc than the specification needs. One source, IspatGuru, describes the next step on a continuous line: high-pressure air removes any excess molten zinc to create a closely controlled coating thickness. We found no second neutral source for wiping, so treat it as that source’s account of a continuous line, not of every wire mill.
6. Cooling
The last step is cooling. IspatGuru says the steel is cooled to allow the metal to solidify onto the steel surface, and Wikipedia describes a quench tank that lowers the temperature and limits reactions between the new coating and the air.
What the neutral sources do not tell us
Most published descriptions are written for structural steel, parts and strip. The sources we fetched name wire as one product of the continuous process, and none gives the settings of a wire line. We therefore state no bath temperature, time in the bath, line speed or zinc chemistry. If one matters for your use, ask for it in the quotation.
How the process sets coating mass
The zinc on a wire is not measured as a thickness on the order. For steel wire, EN 10244-2 specifies the requirements for coating mass, other properties and testing of zinc and zinc alloy coatings on steel wire. ASTM A641 covers zinc-coated carbon steel wire in coils and sets a minimum zinc mass for each coating class. In both, the unit is grams of zinc per square metre of wire surface, written g/m², and the required mass depends on the diameter.
The association states that the service life of a zinc coating is a linear function of its thickness, so more zinc gives a longer life in the same setting. Because the bath builds the coating and the exit of the bath trims it, coating mass is the output of the process that you can compare between offers. Our guide to zinc coating classes shows how each standard writes the classes. Strength is named separately; see galvanized wire tensile strength.
Hot-dip or electro-galvanized
Electro-galvanizing bonds zinc to the steel with electric current and gives a thinner coating than the bath described above. Our guide to hot-dip vs electro-galvanized wire compares the two, so we do not repeat it here. The wire Reinwent sources is hot-dip galvanized.
What to state in an RFQ
The specification is how you tell the mill what to run. A request is complete when it gives:
- Process: hot-dip galvanized, with electro-galvanized named only if you want it.
- Diameter in millimetres. Convert any gauge number first with the wire gauge chart.
- Coating mass in g/m², or the class, and the standard it belongs to: EN 10244-2, ASTM A641 or the one your market uses.
- Temper or tensile band, written separately from the coating.
- Quantity, coil form and destination.
Each of these fields has an explanation in our overview of types of galvanized wire.
Reinwent and galvanized wire
Reinwent supplies hot-dip galvanized wire in diameters from 0.8 to 8 mm, with a coating weight of 50 to 300 g/m², to EN 10244-2 and ASTM A641. For each order we collect offers from manufacturers in Türkiye and line them up on one basis.
A quotation reaches you within 12 hours, and we stay in touch through the whole process. When your specification is ready, request a quote.
