A screw is an extremely useful simple machine. It consists of a circular cylinder that is surrounded by a spiral thread. Many people picture the metal screw that is used to hold together wood, plastic, electronics, and more.
But a screw does much more than that! A screw converts motion, but in this case, it offers a mechanical advantage by converting circular turning motion into linear forward/backward motion.
Screws are used to hold things together, drill holes into things, and even pump liquids. Some good examples of screws are bolts, screws, bottle tops, guitar tuners, light bulbs, faucet taps, and cork openers.
What is a Screw?
A screw is simply an inclined plane around a cylinder. To describe this better, you can view it as a cylinder with a head (solid top) at one end and a pointed tip (like a nail) at the other end. More importantly, it has ridges winding around it. The correct term for the ridges (or grooves) around the shaft or cylinder is thread.
The distance between threads is the same for each screw but is different on other screws. The distance between threads is called a Pitch.
Screws are useful for holding things together. They can pull or push an object together. They can be used to lift heavy items and tighten things too.
Nail and Screw
These two are not the same. Unlike the nail, a screw has ridges around the shaft. It is harder to drive a screw into a piece of wood because the ridges on the screw create a lot of friction and resistance. To drive a screw into the wood, it has to turn in a circular motion by a screwdriver.
Related Post:
- What is a Screw? – Different Parts of the Screw
- 35 Different Types of Screws and Their Uses
- What is the Difference Between Bolt and Screw?
- 30 Different Types of Screw Heads and Their Uses
- Types of Fasteners (Screws, Rivets, and Washers)
Screw Simple Machine Examples
Common examples of screws include:
- Screw pump
- Bulb
- Jar Lid
- Drill Machine
- Bolt
- Bottle Caps
- Faucets
- Car Jack
- Wine Corkscrew
- Gas Tank Cap
- Screws
- Guitar tuners
- Light Bulb
- Ball Point Pens
- Circular Stairways
1. Screw Pump
As the name itself indicates, a screw pump is an example of a simple screw machine. A screw can be used to pump water from a lower elevation to a higher one. The machine uses multiple screws to use the positive displacement theory and move fluid along.
While this is commonly called an Archimedes’ Screw since it is credited after his invention, it should be noted that there is evidence of a screw pump being used for irrigation before he was even born.
Related Post: What is Screw Pump? | How Do Screw Pump Work?
2. Bulb
To fix a bulb in the holder it is supplied with a sufficient amount of twisting force. The twisting force helps the bulb to rotate. The thread cuttings present on the base of the bulb and inside the holder get perfectly fit with each other, thereby making the bulb one of the prime examples of a simple screw machine.
3. Jar Lid
The threads of the neck of the jar match the threads in the jar lid. For making the jar lid closed, we will match the lid treads with the jar. For doing so, torsion force is applied to the lid that helps in closing the jar. If the force is applied in the opposite direction, the lid is closed. The mechanism is very similar to screw simple machines.
4. Drill Machine
A drilling machine is a fast and strong electric machine to make holes in the surface. The drilling also moves in rotation with threaded pins to make smooth and easy holes in walls or woods. The electric force is applied to the drill machine and work is done. It is also a good example of a simple screw machine.
5. Bolt
A bolt is one of the simplest examples of a simple screw machine. It is a mechanical tool that is used to hold the two objects together with the help of a washer and a nut. The bolt has thread cuttings all over its length that perfectly match the threads on the inside of a nut.
6. Bottle Caps
We often tend to believe that a machine is something that consists of a complex mechanical arrangement of objects by overlooking the existence of machines that we use in our daily life. For instance, the process of fastening and unfastening a bottle cap is based on the working of a simple screw machine.
7. Faucets
The faucets used to control the flow of water or any other fluid are yet another example of simple screw machines. To vary the flow of water coming out of a faucet, it is twisted in a clockwise or anticlockwise direction, thereby exhibiting the operation of a screw machine.
8. Car Jack
A screw jack is a device that is used to convert rotational motion into linear motion. The threads present on the structure of a worm screw or a screw jack are used to push or pull the object depending upon the direction of the rotation.
A car jack is usually small and portable; however, it possesses the ability to carry the weight of the car. Hence, it is one of the chief examples of a screw machine.
9. Wine Corkscrew
A corkscrew is a simple metallic screw attached to the base of a wooden handle. To open a wine bottle with the help of a wine corkscrew, the user firmly grips the arrangement and applies torsion force to it until the screw gets properly embedded into the cork.
The cork then can be easily extracted with a vertical pull, thereby making the wine corkscrew a perfect example of simple screw machines.
10. Gas Tank Cap
We often do not acknowledge the presence of some appliances that we use on the daily basis as simple machines. One such example is a gas tank cap. To fix the gas tank cap on the top of a fuel tank, a torsion force is applied to it that helps it work as a simple screw machine.
11. Screws
Have you noticed your wood material is fixed into your wall through the small pointed piece of the fastener, holding your piece of the frame or painting on your house wall?
This simple yet effective machine is known to be a screw, another awesome home example of a simple machine.
The screw seems like a bolt but the difference is its length, diameter and sharp pointing from the end. The circular spiral threading is just the same as the bolt.
12. Guitar Tuners
Have you seen those guitars closely having some knobs upside?
Those knobs are called Guitar tuners and they are used to tune the guitar as per guitar player requirements or likes. As those knobs or taps can be tightened or loosened up, This function of these guitar tuners knobs makes a perfect example of a screw.
These knobs also have spiral threads which allow players to lose or tighten those knobs according to his/her need.
13. Light Bulb
Have you fixed a bulb in its holder or socket inside your house?
If yes, Then you have noticed that you have to rotate your hand to perfectly fix those light bulbs to further light your home.
This twist and turn with the help of the thread presented on the light bulb make this an effective home example of a screw.
14. Ball Point Pens
You have definitely used a ball pen to write something or make notes or grocery lists on paper.
But, Have you noticed those pen caps upward or in center of the pen, given to refill the ink if gets empty?
If yes, then this ball pen is another awesome exhibition of a screw simple machine. The pen cap has spiral circular threading to tighten or open the cap if needed.
15. Spiral Stairways
A stair which has a spiral shape from bottom to top attached with a long column is known as a spiral staircase or circular staircase.
The purpose of these spiral stairs is to fit into the limited amount of space. But, You may ask how these spiral stairs are examples of screws?
So, here is the answer-
As you noticed those stairs make similar spiral thread shapes as you have seen in the above examples. These circular stairs are also a perfect example of an Incline Plane as you can notice the inclination angle from top to bottom.