For almost two millennia threaded bolts and screws have helped power some of the most important inventions in human history. The vast array of choices available can be overwhelming, and it is important to have the right knowledge to match fasteners properly. In this article Bayou City Bolt presents a simplified overview of the basics of Inch bolts and Metric bolts to help you keep track of the many different variations.
Identifying the inch or metric designation of your bolts is the first step to ensuring you are using correctly-mated parts. Most fasteners will feature some sort of marking on the head or top of the screw to help you determine what standard they follow. This may be a letter, a number or even an arrow to indicate which direction the threads face. If there are no visible markings, the best option is to take a basic inch and metric ruler to the hardware store with you. Record the outside diameter (OD) of the bolt in both inches and millimeters, and count the number of threads within an inch to identify the Thread Pitch (TPI). Compare these measurements to the chart to identify a suitable match.
Inch bolts are usually labeled with the OD, TPI and length in both inches and metric increments. The size of the nut or washer that will be used with the bolt is also included in the tag. Metric bolts are labeled with an “M” followed by the OD and the TPI. For example, an M8 bolt size indicates a 8 millimeter OD with a 8.4 TPI.
Most common bolts are made from steel. This material offers a combination of strength, durability and corrosion resistance. Some bolts, however, are made from alternative metals or polymers. These materials offer a variety of advantages over steel, including lower weight and more versatility. In addition, some materials such as brass and bronze have a natural resistance to corrosion.
A wide range of finishes is also available for Inch bolts to further protect and enhance their performance. Hot-dipped galvanized bolts, for instance, are coated with a thick layer of Zinc to ensure they are resistant to rust and corrosion in outdoor applications. Other coating options include plain (unslotted) and hex head bolts.
Inch bolts are often used in construction to anchor walls and beams. In gardens, parks and playgrounds they are used to secure benches and other equipment to concrete surfaces. In industrial settings, they are used to secure machinery like presses and conveyor belts to the floor of the facility. While these are the most common uses of bolts, they can also be found in a variety of other applications. With the proper knowledge, it is easy to select the best Inch bolts for your project. Simply follow the tips provided in this article and remember that, when in doubt, it is always better to choose a higher quality bolt to avoid premature failure or safety issues.