Choosing the right screw for your project can make or break it. The most important consideration is the size of the hole into which you will be driving the screw. But, there are other things to consider as well, including screw head types, drive types and thread types. There are even different materials from which screws can be made, each with varying properties related to strength, hardness and finish.
The simplest way to determine what screw size you need is by using a thread chart that has a scale showing both the diameter and the number of threads per inch. For example, a #1 screw is a 1/8-inch wide screw with 12 threads per inch.
Screws are measured in either the imperial or the metric system, and you will need to know which one is used where you’re shopping. The imperial screw sizes are listed by both the diameter (including the teeth) and length, while the metric screws are only rated by their diameter and length.
The most common screw sizes are #0, #6, and #8, but the size you need will depend on the task at hand. For example, if you’re attaching trim or molding, you will probably want to use a specialized trim screw with a smaller head. These screw heads are tapered so they will insert beneath the surface of the wood, leaving a small hole that can be filled with wood putty.
Another thing to consider when determining the correct screw size is whether or not you need a coarse or fine thread. Coarse threads can withstand more stress, but are less likely to damage the material, while fine threads offer a tighter fit, but may be prone to tearing. screw sizes