Screw – one of the six simple machines.
Screw: An inclined plane wrapped around a shaft or cylinder. This inclined plane allows the screw to move itself or to move an object or material surrounding it when rotated. Examples: Bolt, Spiral Staircase
- Bolt – a type of fastener that has a threaded head or pin at one end which is inserted into a hole and secured by a nut. It holds and compresses materials together, and it sometimes has a plain shank. Unlike a screw, a bolt does not need to be turned in order to tighten it.
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 majority of screws are tightened by clockwise rotation, which is termed a right-hand thread; a common mnemonic device for remembering this when working with screws or bolts is “righty-tighty, lefty-loosey.”
Types of screws for a quick and strong way to attach things together. They come in many different shapes and sizes, designed for specific applications.
There are screws for just about every material you can think of: Softwood, hardwood, treated lumber, MDF, sheetrock, sheet metal. Head styles come in flat head, pan head or washer head, driver styles range from Phillips to Torx to hex-head to what looks like a proprietary take on Pozidrive, and the finishes offered correspond with whether you’re using their screws indoors or outdoors.
- Surgical screws – for internal repair of bone fractures and breaks. Employed alone or in combination with surgical plates, bolts, rods or nails, surgical screws compress cracked and broken bones; this allows mending with new bone-cell growth.
Detroit Airport parking structure – helix Double-threaded circular helices (96-feet O.D.) are provided at the north and south ends of the structure to provide for vertical automobile circulation, both up and down. These helices provide flexibility to vary the parking supply.
Archimedes’ screw, third century b.c. – The Greek scientist is believed to have designed one of the first water pumps, a rotating corkscrew that pushed water up a tube. It transformed irrigation and remains in use today at many sewage-treatment plants.
- Archimedes Screw – is a positive displacement pump, which takes fluid from a source and forces it to another location, where it is discharged. The pump consists of an auger (helix) contained within a tight fitting cylinder, and the blades of the helix create individual pockets between the auger and the wall of the cylinder.
- Screw Pump Design (video 3:49) – To design an effective screw pump device (Archimedes screw), designers have to work within external constraints, including: i) Radius of the screw’s outer cylinder, ii) Total length from the bottom to the top and iii) Slope of the screw pump.
What’s the problem?’
Outlaw fastners – a team of guys comprised of an industrial designer, a mechanical engineer, a contractor and “some business guys” reckoned they could invent a better deck screw, and having put in two years of development time, they’ll shortly be bringing it to market.
- Ask – The most common uses of screws are to hold objects together — such as wood — and to position objects. How big are the objects to be joined? What sort of material are they?
- Imagine – Bolts are a form of screw. They usually go through a hole and are held in place by a nut. What are other types of fasteners? What can be joined without fasteners? How does that work?
- Design, Build – When would a screw be the best choice to hold things together? How can a circular helix or screw help move thousands of cars?
- Improve – Most families have have screws and a screwdriver for making small repairs. Some screws can be hammered in, but removed with a screw driver. What would make using screws better?
- Mechanical advantage – the number of times a machine multiplies your effort force
- A ] is a shaft with a helical groove formed on its surface. Its main uses are as a threaded fastener used to hold objects together, and as a simple machine used to translate torque into linear force.
- mechanical advantage, thread, force, Screw driver, Wrench, bolt, nut, torque, linear helical, grove, surface
Here are some challenges for you to work on…
- Explain how an Archimedes Screw is used to lift and move water
- Hand-Operated Water Pump (Archimedes’ Screw) – How can water climb while “descending”? Doesn’t it seem contradictory? Make your own water pump and find the answer. PVC pipe 1.6 ft (0.5 m) long, transparent plastic tubing, 1 yd (1 m) long
- Creo Elements/Direct Modeling Personal Edition – Download this free 3D CAD software and create assemblies with up to 60 unique parts. Use it as long as you like. Create and modify design data in real-time Edit work with direct cut-and paste, push-and-pull and drag-and-drop techniques. Explore concepts and variations using a direct 3D CAD approach
- 11,492 Spaces – Detroit Airport Unveils Largest Parking Structure Ever Built!