Screws play a key role in an endless number of construction tasks, from woodworking to metal roof installations. Choosing the right screw size for a job can mean the difference between success and failure. Incorrectly-sized screws can split wood, break through drywall and damage other materials. That’s why it’s important to understand the three essential screw measurements: gauge, threads per inch and shaft length in inches.
The first measurement is the screw’s gauge, which refers to its thickness. Gauge sizes range from 2 to 16, with 8-gauge screws generally considered a good all-purpose size for general construction projects. Thicker materials require thicker screws, while thinner material can be secured with a thinner screw.
Secondly, you’ll want to consider the screw’s thread count, which is measured by counting the number of thread peaks that run along a one-inch length of screw. The higher the thread count, the more tight-fitting the screw is, while lower thread counts indicate a looser fit. Screws with coarse threads have a larger diameter than those with fine threads.
Finally, you’ll need to consider the screw’s length, which is determined by how deep into the material it needs to go. The longer the screw, the deeper into the material it will go and the more weight it will support. Using the proper screw length will ensure that your fasteners have adequate shear strength for the job, as well as maintain their structural integrity in use. 1/8 in to mm