Why Add Zinc to Steel?

*This is the second in a four-part series about steel used in rigging supplies and rigging hardware.

As explained in the previous post about carbon steel, there are four main types, and two of those involve a layer to add zinc to steel. These two types are hot galvanized dipped and zinc plated. Both of these styles are extremely popular, and it’s not hard to see why. There are several benefits to doing things this way, but one of the most obvious is that steel can be extremely vulnerable to rust, especially in areas with a heavy exposure to saltwater. Zinc acts as a natural barrier to rust, making the steel more durable to conditions that might otherwise begin to chip away at it.

Why add zinc to steel?

Aside from the obvious benefit of inhibiting rust and protecting the carbon steel underneath, zinc actually does this by oxidizing itself. Think of it as almost as “self-sacrifice” by the zinc that keeps the steel strong. This dramatically increases the life span of the steel, as well. It’s a very short process that takes only minutes to do, and since zinc is common and inexpensive, it’s a natural fit to combine with the steel needed to build a wide variety of goods.

Which is better: hot dipped galvanized steel or zinc coated steel?

There are pros and cons to going either direction.

Hot dipped galvanized coatings may not look as smooth but they tend to last a lot longer. Also, the zinc oxidizes before the steel which means that raw steel is still in better shape to hold up against decay. It lasts a very long time and looks more rugged, but it is also more expensive than a simple zinc coating.

Zinc coated carbon steel is more economical since it is inexpensive. However the coating is much lighter than with hot dipped steel, so the coating will wear away much more quickly – no seventy years of coating here. It does look cleaner and a lot smoother if appearance matters.

Which should you choose?

Not everyone needs the additional sturdiness or durability that comes with a zinc alloy being added to carbon steel, however most people like the idea of making sure their investment is much more likely to rust or buckle under the pressure of time.

While people may disagree over which method is best for them, there’s no question that zinc is a welcome addition to carbon steel in most instances, and the decision towards one or the other will depend on the applications the zinc-coated equipment will be used in.