While numerous different fastener materials are available, including popular choices such as stainless steel and aluminium, the selection of a fastener’s finish (sometimes referred to as a coating) is also essential to ensure that it is compatible with the target application.
With that in mind, let’s take a closer look at some of the most commonly requested finishes and what they offer in terms of benefits and drawbacks.
One of the most popular finishes for steel fasteners is zinc plating. This is because zinc offers good corrosion resistance in many environments, especially when compared to uncoated alloy steel. In fact, zinc plating is often used as a sacrificial anode in order to protect other metals from corrosion.
However, zinc plating is not well-suited for harsh environments where it will be exposed to strong acids or bases, as the finish can be easily damaged. Additionally, zinc is a relatively soft metal, so it is not ideal for applications with high wear and tear levels.
Hot Dip Galvanising
The process of hot dip galvanising involves coating a steel fastener in a layer of molten zinc. This provides excellent corrosion resistance, even in outdoor or marine environments. In fact, hot dip galvanising is often used to extend the lifespan of fasteners exposed to salt water.
Another reason it’s such a popular finish is that it works really well in harsh environments, in contrast to zinc plating. If you need a fastener that is resistant to corrosion and can withstand heavy wear and tear, hot dip galvanising your fasteners is an excellent choice.
Chrome plating fasteners are partly driven by aesthetics, as chrome’s shiny finish is often seen as more attractive than other coatings. However, chrome also offers good levels of wear and tear resistance by reducing friction and increasing abrasion resistance, making it a popular choice for applications such as automotive parts.
That said, chrome is not the most durable finish and can wear off relatively quickly. Additionally, it is not well-suited for outdoor use as it can be corroded by exposure to salt water and other elements.
Increasingly used to enhance the aesthetic of fasteners such as furniture bolts, black oxide is created by reacting oxygen with the metal surface to create a black film. It offers some extra corrosion and abrasion resistance while reducing the reflective property of a fastener, lending itself well to military and industrial applications.
While black oxide is a popular finish, it is not particularly durable and offers only limited protection against corrosion, especially in harsh outdoor environments.
Can Fastener Coatings Prevent Galvanic Corrosion?
Adding a finish to a fastener can help prevent galvanic corrosion or at least slow the process down. Galvanic corrosion is a type of corrosion that occurs when two dissimilar metals are in contact with each other. Adding a finish or a coating, such as those mentioned above, can help isolate the two metals and prevent them from coming into contact with each other.
However, the specific type of finish and its ability to hamper galvanic corrosion will vary depending on the metals involved and the environment in which the fastener will be used. As such, it’s always best to consult an expert to ensure that you’re using the most suitable finish for your needs.
Source Your Coated Fasteners from a Trusted Supplier Today
There are plenty of fastener finishes available, each with its own unique set of benefits and drawbacks. The most important thing is to choose the right finish for your needs in order to ensure the best possible performance from your fasteners.
If you’re looking for coated fasteners for your next project, look no further than Leyton Fasteners. Not only do we stock every conceivable fastener finish under the sun, but our team of experts are always on hand to offer advice and guidance, ensuring that you choose the perfect fastener for your needs.