Let’s make one thing clear. 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 – or any variations of screws either. Our goal is really to shed some light on the times you would want to pick one fastener over another (screw or nail). once you pick the correct fastener, then you can drill down and figure out exactly what type of nail or screw to use – but that won’t be covered here.
Okay let’s jump into this.
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 we 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.
Now here’s the fun part
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.
Conclusion
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.