Screw

Screw

A Screw is a type of fastener, typically made of metal, and characterized by a helical ridge, known as a male thread or just thread. Screws are used to fasten materials by digging in and wedging into a material when turned, while the thread cuts grooves in the fastened material that may help pull fastened materials together and prevent pull-out.

History

The screw was first used in the Ancient Greek era. It was described by Archimedes, who is credited with its invention. The Archimedes' screw, a device for lifting water, is an early application of the screw principle.

Types of Screws

There are many types of screws, each with a particular purpose. Some of the most common types include the wood screw, the machine screw, the sheet metal screw, and the self-drilling screw.

Wood Screw

Wood screws are used primarily for connecting wood to wood. They have a pointed tip and a smooth shank near the head.

Machine Screw

Machine screws are used to hold parts together in machines, appliances, and more. They are available in a variety of head styles and materials.

Sheet Metal Screw

Sheet metal screws are used to attach pieces of sheet metal together. They have a pointed tip and threads that cover the entire length of the screw.

Self-Drilling Screw

Self-drilling screws are used in a variety of applications ranging from DIY hardware to professional construction. They eliminate the need for a pre-drilled hole.

Screw Drive Types

The drive of a screw is the shape or grooving pattern on the screw head that allows a screwdriver to engage the screw. Common types include the slotted drive, Phillips drive, Robertson drive, and Torx drive.

See Also

• Bolt
• Nut
• Washer
• Rivet
• Nail