Characterized by the presence of helical threading around a long shaft, screws are the world’s most common fastener. When two or more solid objects require joining, screws are often used. They offer an easy and effective solution for joining multiple solid objects. While all screws have helical threading around a shaft, though, they aren’t necessarily the same. Below are six common types of screws.
#1) Wood Screw
Perhaps the single most common type of screw is a wood screw. Wood screws aren’t made of actual wood. Rather, they are used to connect two or more solid wooden objects. Wood screws have a sharp point that’s able to dig into wood, making them highly useful for woodworking applications.
#2) Machine Screw
A machine screw, as the name suggests, is a type of screw that’s used in machining applications. There are many different types of machine screws, one type is a stove bolt. Machine screws are used to hold heavy-duty metal objects together. According to Wikipedia, machine screws can have a diameter up to 0.75 inches, making them bigger than most other screws.
#3) Lag Screw
While not as common as wood or machine screws, lag screws are another type of screw worth mentioning. Also known as lag bolts or coach bolts, they are essentially jumbo-sized wood screws coated with zinc. A zinc layer is applied to lag screws to protect them against rust and corrosion. To apply the zinc, companies typically perform electroplating or hot-dip galvanization.
#4) Sheet Metal Screw
Sheet metal screws, of course, are designed to be driven into sheet metal. They can still be used on other materials, such as wood, but they are primarily used for sheet metal. Sheet metal screws have threading all the way up to the shank at the top, allowing them to easily dig into sheet metal.
#5) Twinfast Screw
Twinfast screws feature a unique design consisting of two threads rather than just one. With twice the threading, they can be driven into objects twice as quickly when compared to traditional screws. Most drywall screws are twinfast screws. With that said, twinfast screws can be used for other applications besides the installation and hanging of drywall.
#6) Security Screw
Finally, security screws are designed to protect against removal or tampering. Unlike other screws, security screws don’t have an operable head that can be reversed to remove the screw. Rather, they generally require a specialized tool like a spanner or square driver to remove. This design makes them an excellent choice for security applications.