Choosing the correct screw size is a vital element in the success of any project. A short screw can’t securely hold the material it is working on, and an overly long one may cause damage or protrude from the surface, posing safety hazards. Measuring screw length, diameter and thread pitch is easy with the right tools and knowledge. This article will walk you through the process of measuring a screw, equipping you to choose the best fastener for any project.
To measure a screw’s length, first line it up against a ruler or tape and check its tip for width. This measurement is known as its diameter and can be determined by either imperial or metric units. For imperial units, screw sizes are typically listed with a number and a fraction of an inch; for metric measurements, they’re often listed in millimeters.
The next step is to determine the threads’ depth. To do this, line the screw up against a ruler or tape and calculate how many threads fit in an inch. Then, divide the screw’s diameter by its thread pitch to find out its thread length. For example, a screw with a 6 mm diameter and a 30 tpi pitch has a thread length of 1.5 mm.
Finally, select a screw that’s approximately half as long as the material it will be entering. Anything shorter and the screw will fail to anchor properly, while a screw that’s too long will cause the opposite side of the material to wear or break off. #6 screw size