Screws require the use of a drive system for installation. To install a screw into a workpiece, you must force it into the workpiece using its drive system. The drive system of a screw generally consists of ridges in the screw’s head. Upon placing a compatible screwdriver into the screw’s head and turning it, the screw will dig into the workpiece. So, what are the most common types of screw drives?
#1) Phillips-Head
Arguably, the most common type of screw drive is Phillips head. Developed by American engineer John P. Thompson, it offers a high level of torque to achieve quick and easy installation. Phillips-head screws feature a cross-shaped pattern on the head in which the screwdriver is inserted.
#2) Flat-Head
Also known as a slot drive, a flat-head screw lives up to its namesake by supporting the use of a flat-head screwdriver. Flat-head screws are similar to Phillips-head screws, except they only have two ridges on the head rather than four. The two ridges, both of which run horizontally and on the same plane, allow for the insertion of a flat-head screwdriver.
#3) Hex
While Phillips-head and flat-head are common, another common type of screw drive is hex. Hex screws live up to their namesake by featuring hexagonal ridges on their head. They can be installed using a hex wrench, which like screwdrivers, is inserted into the screw’s head.
#4) Torx
The hexalobular socket drive, or what’s more commonly known as the Torx drive, features star-shaped ridges on the head. The head essentially has six ridges with rounded points. The Torx drive was created to increase torque. Thanks to its star-shaped head, it provides an exceptional amount of torque during installation. Torx screws are often used during the production of computer components and other electronics.
#5) Double Hex
In addition to single hex, another common type of screw drive is double hex. Basically, double hex screws feature two pairs of hexagonal ridges on the head. With twice the ridges, they allow for greater torque during installation. The downside to using double hex screws, however, is that their heads are more susceptible to slippage, as well as damage, than those other types of screws with different drive systems.
#6) Robertson
Also known as Scrulox, the Robertson drive is characterized by square-shaped ridges on the head. It’s slightly tapered, allowing for easy installation. With that said, Robertson screws are most commonly used in Canada. Some companies use them in the United States as well, but they are predominantly used in Canada.