Are you confused by the multitude of screw sizes found in your drawer or the screws used on a project? Jaycon Systems engineers use a variety of screws in their work and it’s important for them to have an understanding of how to select the proper type and size for each application. There are three fundamental qualities that make a screw: the head, the length and the gauge. This article will help you understand these values and select the right screw for your needs.
Screws are generally labeled with two numbers: the gauge (also known as major diameter) and the thread per inch. The first number represents the major diameter and can be converted to a decimal equivalent using Engineering Toolbox’s handy chart. The second number is the number of threads in one inch and is often referred to as the “pitch” or “thread pitch.” It’s common for a single diameter size to have multiple pitches.
The length of the screw is also important. The length of a screw must be sufficient to anchor it in the material that you are working with. It is usually recommended that a screw be at least half as long as the material it is fastening to. Screws that are too short will not anchor well in the material and can damage the opposite side of the material. For this reason it’s important to know the type of material you will be using a screw with when selecting the correct size and gauge. 3/8 in to mm