There are many different types of bolts, each with its own unique features and uses. While outside diameter and thread pitch are common measurements that distinguish one type of fastener from another, many have specific dimensions that set them apart and make them uniquely suited to their intended application. Some of these measurement callouts are readily apparent, such as hex nuts with six sides, while others require a bit more in-depth understanding, like thread designations.
A bolt is a threaded fastener with an attached nut that allows the user to tighten or loosen the bolt using a wrench. Bolts come in a variety of lengths and can be made from carbon steel, stainless steel, bronze, and other materials. They can also be made with a variety of thread styles and strengths. Some bolts are even resistant to corrosion, making them ideal for applications where abrasive metals may damage other components.
Many bolts have markings engraved into their heads, indicating important information about the fastener. These markings can help you determine the bolt’s strength, material composition, and dimensions. The most common markings are letters, numbers, dashes, slashes, and dots. In general, the more information a bolt head has, the stronger it is. Bolt strength is indicated by the grades created by the Society of Automotive Engineers (SAE). These grades communicate valuable information, such as how much stress a bolt can withstand without breaking. The higher the grade, the more stress a bolt can withstand before it breaks.
The material composition of a bolt tells the user what it is made out of, how it will react to environmental factors, and its corrosion resistance. Stainless steel bolts, for example, have excellent corrosion resistance due to their chromium content. These bolts are widely used in food preparation equipment, medical instruments, and hospital tools because of their hygienic qualities. Stainless steel is also easy to fabricate and inexpensive compared to other materials like nickel or titanium.
Some bolts, such as lag screws and plow bolts, have a flange that helps distribute the load. This makes these bolts ideal for tying down heavy lumber or machinery, as well as suspending electrical conduits and fixtures. The flange also protects the threads from damaging surfaces and makes them easier to remove.
Many bolts are coated in a zinc layer, which acts as a protective barrier against the elements. Zinc is also a naturally conductive element, so these bolts are often used in electrical and plumbing projects. Other coatings include aluminum, which is less expensive than stainless steel, and galvanized iron, which is rust resistant. US bolts