Nuts are fasteners that can be made from a variety of metals.
Choosing the right material for nuts/screws is important in the outdoor woodworking job since this will determine how strong the project will be when they are used.
The material will also determine their resistance to corrosion as well as their aesthetic appeal.
Two of the more common types of material used to make nuts are stainless steel and zinc plating.
There are also galvanized nuts which are not so much material, but rather the process used to help make steel more resistant to corrosion.
In the article below we will be looking in detail at what material should you choose when picking the nuts and screws for woodworking projects outside so that they do not get damaged soon.
So, let’s get started…
In this article we will cover:
Stainless Steel Nuts
Stainless steel is known for its durability and resistance to corrosion. Plus, the integrity of the nut will not be affected when scratched or dinged.
The only downside is that when stainless steel nuts are installed, they may cause galling or seizing to occur.
This is why installing stainless steel nuts is normally left to a professional who has the tools to prevent galling from occurring.
Zinc Plated Nuts & Screws
These are basically the steel nuts that are electroplated with zinc.
The zinc provides additional resistance to corrosion and is a popular choice.
Zinc plated nuts and bolts offer a number of uses, including projects that are outdoors since they can resist the elements.
However, they are not fully resistant to water which is why they are not recommended for high humidity or underwater environments.
One noticeable advantage of zinc plated nuts and bolts is the fact that they are far more affordable compared to stainless steel versions.
They are also strong, resist corrosion, and can be used for many different applications.
Galvanized nuts also have a layer of zinc. The difference is that the metal is hot dipped which results in a thicker coating.
This makes them even more resistant to corrosion compared to standard zinc plating.
While galvanized nuts tend to be quite durable, they are not compatible with bolts that are made from other materials.
This is because the galvanized nuts are slightly different in their size.
Stainless Steel vs. Zinc Plated Nuts: What is Better?
Bottom line, the stainless-steel nuts provide all the advantages of being resistant to corrosion, strong, durable, and long-lasting.
Zinc plated nuts will tend to corrode faster compared to their stainless-steel counterparts. This means that zinc plated nuts will not last as long nor are they as durable.
If you have ready access to stainless steel nuts and they are affordable, then they tend to be the better choice.
What to Look Before Buying Woodworking Screws and Nuts?
There are several factors to consider when purchasing the type of screws and nuts that will work best for your project.
From practical to appearance, some of the factors to consider include the following.
a) Length & Gauge:
This is a basic determination based on the thickness of the wood and the type of work being performed.
The length and gauge of the screws and nuts should match the thickness and hardness of the wood.
b) Drive of the Screw:
The type of screw head makes a difference. Most screws use Philip’s head because it is more common and considered easier to drive.
But the star and square drives may work quite well. Basically, the type of head that is easier for you to drive should be the top consideration.
c) Flat or Pan Head:
A flat head is recommended when fastening wood directly to wood.
But if the wood is being fastened to plastic, a pan head is recommended instead.
d) Self-Drilling Tip:
A self-drilling tip can be driven into the wood faster, but there is a higher probability of splitting the wood.
For thick wood that is resistant to splitting, a self-drilling tip may be the right choice.
The application and usage of the material that is being fastened determines in large part what type of screw should be used.
Moist environments lean towards using screws that are corrosion-resistant such as stainless steel.
Dry conditions make for standard iron or steel screws. Be sure to take all that into account when deciding on which type to use.
Are Zinc Coated Screws Rust Proof?
Because they are coated with zinc, the nuts are rust-proof. This means that you can use them in outdoor applications.
They should be replaced with the zinc layer that has fully eroded, leaving the underlying steel exposed.
Electrogalvanized screws also offer protection against the elements and have a shiny, bright appearance.
However, they tend to leave black streaks around the nail area.
Instead, you should use mechanical galvanized screws instead for pressure-treated wood. Or, you can go with stainless steel.
It should be noted that zinc-coated screws will break down at some point and start to oxidize faster than stainless steel.
If the project in which the screws are being used is temporary, then it makes no difference.
But if it is supposed to last for a long time, then stainless steel is recommended.
Can You use Zinc Coated Screws in Pressure Treated Wood?
Zinc-coated screws can be used in pressure-treated wood since they will not rust when inside.
However, there are some types of zinc-coated screws that are not best suited for the job.
Electrogalvanized screws will tend to corrode much faster compared to mechanical galvanized screws, so they should be used instead.
If the screws are to be used in pressure-treated wood that is exposed to a high salt or moisture environment, then zinc-coated screws should not be used at all.
What Type of Screws and Nails Must Be Used in Pressure Treated Lumber?
Galvanized screws and nails that are hot-dipped are generally the best for most projects.
Keep in mind that such screws should have a protective coating when used in pressure-treated wood.
Other types of screws that are well suited for pressure-treated lumber include the following.
Polymer Protected: This is a non-reactive organic polymer coating that is placed over the zinc coating for better protection.
This is to protect copper-treated wood from becoming corroded. It also prevents both copper and water from touching the steel or zinc inside the screws.
Stainless Fasteners: It’s best to choose either grades 304 or 305 which provides good corrosion resistance.
However, for copper-treated wood, grade 316 is generally the best when used in coastal areas.
Keep in mind that they tend to be more expensive and cannot be used with galvanized structural connectors because of the potential chemical reaction.
Nuts and screws you use in woodwork are most associated with steel, but they can also be made of titanium, plastic, or other materials.
In addition to the materials, nuts come in different grades as well. Some may have coatings to enhance their rust protection or make them stronger, so they last longer.
For replacing nuts or screws (used in your fence, sheds, or other outdoor furniture), you should first use nuts of the same material unless it is causing corrosion.
And when buying the new ones for your fresh project, it’s important to look at the environmental conditions they will be exposed to along with the factors I have mentioned above.
Hi, I am Mark Garner a professional carpenter, woodworker, and DIY painter. I live in the small city of Peoria, Arizona as a semi-retired woodworker. I have started this blog with a simple motive to help you with my wood experience in this sector. If you like to know more about what I love doing and how it all got started, you can check more about me here.