How Can I Prevent Screws From Rusting?
We use screws for fixing and joining materials because they provide a strong grip that is robust and long-lasting, providing we choose the correct type of screw for the application we are undertaking. But sometimes the screw doesn’t perform as well as we expect. There can be many reasons for this. As mentioned above, we can use the wrong type of screw (in terms of size, type or material), we can badly install it using the wrong tools or techniques, or the screw itself can start to deteriorate, and the most common cause of that is rust.
What is rust?
Rust is the result of a chemical reaction of an iron surface with oxygen and the presence of moisture, which can be in the form of water or air moisture. The initial result of this chemical reaction is a light dust or a flaky and brittle surface which is reddish-brown in colour and is essentially an iron oxide. Rusting is a type of corrosion which is seen in iron and most commonly in its alloy steel. Over time, further corrosion can occur and the rusting can grow to deteriorate the mechanical structure of the metal and therefore its strength, and in extreme cases a metal can turn completely to rust.
Because rust can destabilise a metal and affect its functionality, we need to implement some preventive measures to stop this chemical reaction occurring, or at least to slow it down. In some cases this could be more vigilant observation to spot signs of rusting before they become damaging, but it is much easier to simply prevent moisture from reaching a part, or to use a material that doesn’t corrode in this way, or corrodes more slowly.
The best ways to prevent screws from rusting
Many people would recommend the use of oils or lubricants, such as WD40, to prevent rusting and ensure the screw still performs as it should. The oil content of these types of lubricant works to inhibit moisture and prevents it reaching the iron in the metal. However, while this will work in many situations, you do have to be careful in which application you use this method, because using oil and lubricants can alter the torque values of screws and reduce the friction between the screw and the nut, or between the screw and a thread. This friction is fundamental to the purpose of the screw and the job you need it to do. Furthermore, if this lubricant is applied during the initial installation of the screw, the lack of friction could cause you to over-tighten the screw during the application, which in turn can lead to the screw or fixed material being damaged.
It is also possible to paint a screw to prevent moisture access. Again, this can work to an extent, but paint can flake off and won’t resist moisture long-term, so this method is merely slowing down the rusting process rather than eliminating it altogether.
The use of materials which don’t corrode is probably the most full proof way of preventing rust. Galvanised screws are zinc-plated and this is a process which corrodes slower and so will prevent rust for a period of time, however, the best way to prevent rust altogether is to use stainless steel screws. Stainless steel is an iron alloy that contains traces of chromium and carbon, which combine to prevent the metal from corroding. There are now over 100 different grades of stainless steel which are used for many different applications, but stainless steel screws are now very common and the most popular type of screw due to their versatility and anti-corrosion qualities.
Contact MB Direct for advice on using screws that don’t rust
If we are working on an application that will be used or stored outside, such as industrial tanks, storage containers, external racks or shelving, we should always use stainless steel screws and fixings. We can’t avoid these items being exposed to the elements, and even if they are sheltered from rain and the main excesses of the UK weather, there will still be sufficient moisture in the air to cause rusting to a metal, even if the reaction is a little slower than direct contact with water.
So stainless steel screws are the best way to prevent screws from rusting and at MB Direct we supply a vast range of screws and fixings made from stainless steel and which will be suitable for the application you are involved in. So contact our team at MB Direct today and we can advise on the best screws to use for preventing rust and which are appropriate for your needs.