Why are there so many fasteners on the market. We have screws, nails, staples, glue, velcro and so many other ways to fasten things to each other. Well the reality is different applications take different types of fasteners. I recently built a corner shelf for my TV, which someday I will get to writing that article. For this simple and small project, I used three different types of fasteners. I used nails, screws and glue. To add even more I used two different types of nails. I used finish nails and framing nails. Most of the time people know when to use glue over a nail or a screw over a staple. however there is still a lot of questions we see coming up where people are really not sure when to use a nail or when to use a screw. So as always we like to try and make things more clear. Well before we go on, this is going to be an overview of when to use a nail over a screw. We are not going to get into the differences between a framing nail and a finish nail or a galvanized nail vs a nail with adhesive on the tips. Our goal is really to shed some light on the times you would want to pick one fastener over another. once you pick the correct fastener, then you can drill down and figure out exactly what type of nail or screw to use. Okay let’s jump into this.
Difference Between Nails and Screws
You can see by the pictures below a screw and a nail have some very different features from each other. A screw has threads on the shaft while a nail is smooth. Since that is the case, a smooth nail can be fastened to a material using a hammer or any pounding force. Since a screw has threads, you can not use a hammer, you need a screwdriver or some tool that turns the screw into the material. Hence that is why on the top of a nail, the head is flat, while the screw has a dimple for a philips, flat head or another type of tool to do the turning.
So now that you know the difference between a screw and a nail, let’s jump into when to use each one.
When to Use a Screw or Nail
Now the big question. When do I use a screw and when do I use a nail. If you have anything that has sideways pressure where material would have the tendency to move left or right, this is when you would use a nail. When I say left or right, it really is the sideways movement. If you have material that will try and separate from the top or bottom, then you use a screw.
Lets go back to my corner shelf example. I built a corner shelf in my living room for my TV. I had to fasten a 2×4 horizontally on the wall and make a triangle. This way I can set the plywood on top and then the TV would sit on that. To fasten the 2×4, I used nails since the weight of the TV will be pushing down on the 2×4. There is sideways pressure and that is why I used nails. Once that was in place, I secured the plywood to the 2×4 with screws. The reason is because the 2×4 will have up and down pressure meaning the plywood will not have any sideways pressure. If I were to use nails here, over time the nails would come free and break through the paint.
Test the Theory
If you want to see how these two really differ from each other, grab two nails, two screws and some wood. Pound the nails about halfway in. Screw the screws about halfway into the wood. Okay using your claw side of your hammer, pull straight up on the nail and straight up on the screw. Which one comes out easier? The nail. The screw is extremely hard. This shows how much more up and down pressure a screw has to hold material together.
Now you should have a nail and screw left over that are still halfway into the wood. Grab your hammer again and pound sideways on the nail and sideways on the screw. What happens? The nail just bends, but stays in place in the wood and is solid in the wood. Not much movement. However the screw either broke or now has a lot of play in the wood where it is loose. As you can see the nail is great for sideways pressure, while the screw will not hold over time.
As you can see by the experiment that is why people use nails for framing. When you have a frame, you will be getting a lot more side to side pressure. However when you hang drywall, you use a screw because the up and down pressure is the greatest. If you were to use nails in drywall, over time you would see the nail heads popping out.
There is more to this whole concept, but again we wanted to make this a little easier for you to determine when to use a screw and when to use a nail.