Why screws are used

The bolt is then pushed through the drilled hole. Next, a nut is placed at the end to screw the bolt through. There are many different sizes of screws, nuts and bolts. The drill bit is also a screw and can make holes in nearly every surface including wood, plastic, metal, and stones when attached to an electric drill.

It also has threads and is pointed at one end. The grooves are deeper on a drill bit because they carry pieces of the wood or other material from the hole to the surface as the drill bit turns.

A screw having threads close together has a mechanical advantage over those with wider spaces. They will take less force but more turns. Those with wider spaces will take more force but less turns. They have a corkscrew-shaped ridge, known as a thread, wrapped around a cylinder. The head is specially shaped to allow a screwdriver or wrench to grip the screw when driving it in.

The most common uses of screws are to hold objects together — such as wood — and to position objects. Often screws have a head on one end of the screw that allows it to be turned. The head is usually larger than the body of the screw. The cylindrical portion of the screw from the underside of the head to the tip is called the shank.

Bolts are a type of screw that usually is designed to work with a nut or another threaded fastener. Historians do not know who invented the screw. Although it seems to have been invented only in the last few thousand years. The first known use of a screw was as part of the screw pump of Sennacherib, King of Assyria, for the water systems at the Hanging Gardens of Babylon and Nineveh in the 7th century BC.

Around BC, the Greek inventor Archimedes made a screw pump. Archimedes' machine had a revolving screw-shaped blade inside a cylinder. The blade was turned by hand. This type of machine is called the Archimedes screw. It is still used today for pumping liquids and other materials like coal and grain. By the 1st century BC, wooden screws were commonly used throughout the Mediterranean world in devices such as oil and wine presses.

The metal screw did not become a common fastener until machines for mass production were developed at the end of the 18th century, because nails, which are straight, are much easier to make than screws. In the s, English instrument maker Jesse Ramsden invented a machine that made metal screws.

Handheld screwdrivers first appeared around These developments caused a great increase in the use of threaded fasteners. Throughout the 19th century, the most common types of screw heads were round with simple slots that were turned using screwdrivers and square and hexagonal heads that were turned with wrenches. In the early s, the Phillips-head screw was invented by Henry F. This screw has a cross-shaped recess in the head for the driver tool.

Bolts and screws are two standard options, which brings us to a common question:. When it comes to the bolts vs. Screws are a versatile fastener, which makes them a favorite choice. They provide a secure grip thanks to their threads and they meet the needs of numerous do-it-yourself DIY projects. They come in a variety of sizes and types for wood, metal, drywall and even concrete applications. Screws are designed to be self-tapping, but in many cases you may still want to drill a pilot hole.

While you can rely on the DIY "hack" of using a nail to drive your pilot hole, a cordless or corded power drill provides better results. Drills also make the installation — or even removal — of screws easier compared to a handheld screwdriver. Bolts provide the best holding strength compared to screws and other fasteners. Thanks to their threads, bolts can provide an unparalleled level of holding power.

They do require a nut and a washer for their installation. The washer helps to spread the load over a larger surface area, which reduces the wear and tear as well as the loosening of your bolt over time while the nut secures the bolt in place. Like screws, bolts come in many sizes and types. Installing a bolt requires a handheld or pneumatic wrench to remove or install it.

Compared to screws, bolts can be easier to remove. The benefit of a pneumatic wrench is that it provides much more torque than a handheld tool, which makes your job easier. Having a general understanding of bolts and screws will help you decide when to use bolts instead of screws.

Before choosing a side in the bolts vs. Your project is the biggest factor in whether you use screws or bolts. Remember: bolts provide a tremendous amount of holding strength whereas screws offer a middle-ground for holding power. Light to medium construction projects, like for fencing or framing, are best for screws. Your heavy-duty projects are best for bolts. Bolts are also best when the finished project is meant to be assembled and disassembled easily.

Material matters. There are some materials that could require either a screw or a bolt assembly for fastening. Be sure to consider the load being put on the fastener in combination with the material when choosing between bolts and screws. While using bolts can be more costly, using the correct fastener will save you money in the long run.