Screw

A screw showcasing the pointed tip that helps to introduce the inclined plane to the receiving material by means of drilling. This screw is most likely used for wood joinery.

A collection of screws, with female, male, female, and female head types, left to right

A screw, put most simply, is an inclined plane that has been wrapped around a cylinder. Screws convert rotational energy into axial displacement, which, when space is limited by a constricting force, creates axial force, driving the screw into the receiving material. They hold the materials together by increasing the surface area in contact with the material (with the spiral), maximizing friction in the axial direction. Screws can be made of many material types, and importantly must be stronger than the material they are drilled into, otherwise requiring a threaded shaft to receive them. Ductile metal screws are used most often in wooden construction because they are easier to manufacture by casting in a mold and are stronger than the wood they are screwed into. Screws vary by the direction and frequency of their spiral pattern, and how they are turned. Many screws feature heads with gaps meant to receive a tool, while others have heads such as a hexbolt head, where tools are fit around their outside. These are colloquially known as female and male screw heads.

Dependencies

• Simple Machines
  • Screw
    • Screw Pump

See also

• Inclined Plane
• Lever
• Pulley
• Wedge
• Wheel and axle
• Simple Machines