Screw

A screw is a type of fastener, sometimes similar to a bolt (see Differentiation between bolt and screw below), typically made of metal, and characterized by a helical ridge, known as a male thread (external thread) or just thread. A screw is an inclined plane wrapped around a nail. Some screw threads are designed to mate with a complementary thread, known as a female thread (internal thread), often in the form of a nut or an object that has the internal thread formed into it. Other screw threads are designed to cut a helical groove in a softer material as the screw is inserted. The most common uses of screws are to hold objects together and to position objects.

A screw will usually have a head on one end that contains a specially formed shape that allows it to be turned, or driven, with a tool. Common tools for driving screws include screwdrivers and wrenches. The head is usually larger than the body of the screw, which keeps the screw from being driven deeper than the length of the screw and to provide a bearing surface. There are exceptions; for instance, carriage bolts have a domed head that is not designed to be driven; set screws often have a head smaller than the outer diameter of the screw; J-bolts have a J-shaped head which is not designed to be driven, but rather is usually sunk into concrete allowing it to be used as an anchor bolt. The cylindrical portion of the screw from the underside of the head to the tip is known as the shank; it may be fully threaded or partially threaded. The distance between each thread is called the "pitch".

Screw (card game)

Screw, Moonshine, or Popcorn is a card game where the players try to be the first to lose all their cards. Like Palase, it is derived from the Finnish card game Paskahousu.

Rules

Chopped and screwed

Chopped and screwed (sometimes called screwed and chopped or slowed and throwed) refers to a technique of remixing hip hop music which developed in the Houston hip hop scene in the 1990s. This is accomplished by slowing the tempo down to between 60 and 70 quarter-note beats per minute and applying techniques such as skipping beats, record scratching, stop-time, and affecting portions of the music to make a "chopped-up" version of the original. DJ Screw is largely recognized as the innovator behind the chopped and screwed genre. DJ Screw's key technique involved playing the same record on both turntables with a delay between them of one beat, and quickly moving the crossfader side to side. This created an effect where words or sounds would be repeated in the music but would still keep the tempo going. A subgenre called ChopNotSlop created by hailmasch"hailmasch has received major attention via Drake's album and the Houston music scene started by SUC.

History

Screw (disambiguation)

A screw is an externally threaded fastener. "Screw" may also refer to:

Screw (song)

"Screw" (stylized as SCREW) was 14th single by the J-pop singer, Kotoko, was released on December 16, 2009. The title track was used as the theme song for Mamoru Oshii's film Assault Girls.

The single comes in a limited CD+DVD edition (GNCV-0022) and a regular CD-only edition (GNCV-0023). The DVD contains the promotional video for "SCREW".

Track listing

Charts and sales

References

Screw theory

Screw theory is the algebra and calculus of pairs of vectors, such as forces and moments and angular and linear velocity, that arise in the kinematics and dynamics of rigid bodies. The mathematical framework was developed by Sir Robert Stawell Ball in 1876 for application in kinematics and statics of mechanisms (rigid body mechanics).

Screw theory provides a mathematical formulation for the geometry of lines which is central to rigid body dynamics, where lines form the screw axes of spatial movement and the lines of action of forces. The pair of vectors that form the Plücker coordinates of a line define a unit screw, and general screws are obtained by multiplication by a pair of real numbers and addition of vectors.

An important result of screw theory is that geometric calculations for points using vectors have parallel geometric calculations for lines obtained by replacing vectors with screws. This is termed the transfer principle.

Screw theory has become an important tool in robot mechanics, mechanical design, computational geometry and multibody dynamics. This is in part because of the relationship between screws and dual quaternions which have been used to interpolate rigid-body motions. Based on screw theory, an efficient approach has also been developed for the type synthesis of parallel mechanisms (parallel manipulators or parallel robots).