Introduction
Screws are one of the most important and versatile fastening methods available to us today. They are commonly used in all types of structures, from cars and boats, to homes and office buildings. A screw is basically a metal rod with ridges or threads running along the shaft. The screw is driven into a predrilled hole, then the threads catch the material that is being fastened and hold it in place.
Screws come in a variety of different shapes and sizes and are used for many different purposes. It is important to select the right type of screw for the job at hand. If a screw is too large or too small, or it is made of the wrong material, it can cause serious damage to the materials that are being fastened. Selecting the right type of screw requires knowledge of the different types of screws and their associated terminology.
Terminology
Commonly used terms related to screws include:
Phillips head: The Phillips head is the most common type of screw head. It features a cross-shaped head that is used to turn the screw.
Slotted head: A slotted head is a relatively flat-head screw with a straight line indentation. These are designed to fit a flat screwdriver into the slot.
Hex head: Hex heads are designed for use with an Allen wrench. These have a hexagonal-shaped recess which creates more gripping power.
Socket head: Socket head screws feature a cylindrical head with a recessed hexagonal indentation. These are used to create a tighter grip on the screw.
Cap head: A cap head features a rounded top that is designed to provide a flush finish.
Torx head: Torx head screws feature a star-shaped recess in the head. These screws provide a secure fit and are designed to resist tampering.
Threads: Threads are the ridges that run along the screw shaft. They are designed to grip the material and hold the screw in place.
Pitch: Pitch is the distance between the tops of two adjacent threads. The distance is usually marked on the screw head.
Point: The point of the screw is the sharp end of the screw which is designed to penetrate the material.
Length: The length of a screw is the distance from the top of the head to the end of the point.
Conclusion
Screws are one of the most common and versatile fastening methods available. Understanding the different types of screws and associated terminology will help you choose the right screw for the job. Remember, the wrong type of screw or incorrect size can cause serious damage to the materials being fastened, which should be avoided.
