Screw thread, used to convert torque into the linear force in the flood gate. The operator rotates the two long vertical bolts (via bevel gear).

Internal and external threads illustrated using a common nut and bolt.

The screw and nut pair can be used to convert torque into linear force. As the screw (or bolt) is rotated, the screw moves along its axis through the fixed nut, or the non-rotating nut moves along the lead-screw. A screw thread is a helical or tapered structure used to convert between rotational and linear movement or force. Image File history File links Download high resolution version (2582x1827, 667 KB) The small flood gate in Dubendorf, Switzerland. ... Image File history File links Download high resolution version (2582x1827, 667 KB) The small flood gate in Dubendorf, Switzerland. ... Tokyo floodgates to protect from typhoon surges. ... Bevel gear in floodgate Bevel gear - the gear, where the axes of the two shafts cross at points and the gears themselves are conically shaped. ... Image File history File linksMetadata Internal_and_External_Thread. ... Image File history File linksMetadata Internal_and_External_Thread. ... In electrical and mechanical trades and manufacturing, each of a pair of mating connectors or fasteners is conventionally assigned the designation male or female. ... In electrical and mechanical trades and manufacturing, each of a pair of mating connectors or fasteners is conventionally assigned the designation male or female. ... A helix (pl: helices), from the Greek word έλικας/έλιξ, is a twisted shape like a spring, screw or a spiral staircase. ...

Screw threads have several applications:

• Fasteners such as wood screws, machine screws, nuts and bolts.
• Connecting threaded pipes and hoses to each other and to caps and fixtures.
• The worm gear and similar mechanical connections, used particularly in adjustment mechanisms.

In all of these applications, the screw thread has two main functions: Screws come in a variety of shapes and sizes for different purposes. ... A nut is a type of hardware fastener with a threaded hole. ... There are three kinds of fastener given the name bolt. ... A threaded pipe plug; note that the threaded portion is slightly conical and so touches the calipers at only two points. ... Look up hose in Wiktionary, the free dictionary. ... Worm and worm gear A worm gear, or worm wheel, is a type of gear that engages with a worm to greatly reduce rotational speed, or to allow higher torque to be transmitted. ...

• It converts rotary motion into linear.
• It prevents linear motion without the corresponding rotation.

In most applications, the thread pitch of a screw is chosen so that friction is sufficient to prevent linear motion being converted to rotary, that is so the screw does not slip even when linear force is applied so long as no external rotational force is present. This characteristic is essential to the vast majority of its uses. Three different sets of threading gauges Threading gauges, pictured on the right, are also referred to as pitch gauges and are used to measure the pitch or lead of the screw threads. ... It has been suggested that Coefficient of friction be merged into this article or section. ...

A screw thread may be thought of as an inclined plane wrapped around a cylinder or cone. An inclined plane is a plane surface set at an angle, other than a right angle, against a horizontal surface. ... A right circular cylinder An elliptic cylinder In mathematics, a cylinder is a quadric, i. ... This article needs to be cleaned up to conform to a higher standard of quality. ...

Standard threads

Standards for machine screw threads have existed since the mid nineteenth century, to facilitate compatibility between different manufacturers and users. Many of these standards also specified corresponding bolt head and nut sizes, to facilitate compatibility between spanners and other driving tools. Screws come in a variety of shapes and sizes for different purposes. ... A wrench or spanner is a tool used to turn bolts, nuts or other hard-to-turn items. ...

Nearly all threads are oriented so a bolt or nut, seen from above, is tightened (the item turned moves away from the viewer) by turning it in a clockwise direction, and loosened (the item moves towards the viewer) by turning anticlockwise. This is known as a right handed thread. Threads oriented in the opposite direction are known as left handed. Clockwise can refer to: Clockwise and counterclockwise Clockwise (movie) This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

Left handed threads are used:

• Where the rotation of a shaft would cause a conventional right handed nut to loosen rather than to tighten, e.g. on a left-hand bicycle pedal.
• In combination with right handed threads in turnbuckles.
• In some gas supply connections to prevent dangerous misconnections.
• In antenna connectors on some Wireless LAN access points, to prevent the connection of a non-FCC approved antenna.

Unless stated otherwise, all standards below specify right-handed threads. A bicycle pedal provides the connection between the cyclists foot or shoe and the crankarm allowing the leg to be used to turn the crank. ... A turnbuckle is a device for adjusting the tension in ropes, cables, and tie rods. ... It has been suggested that wireless network interface cards be merged into this article or section. ... A wireless access point (WAP or AP) is a device that connects wireless communication devices together to create a wireless network. ... The FCCs official seal. ...

ISO standard threads

The most common threads in use are the ISO metric screw threads (M). The metric ISO screw threads are the world-wide most commonly used type of general-purpose screw thread. ...

These were standardized by the International Organization for Standardization in 1947. Before that, there were separate metric thread standards used in France, German, and Japan, and the Swiss had a set of threads for watches. The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from national standards bodies. ...

Other current standards

In particular applications, largely for reasons of backwards compatibility, threads other than the ISO metric threads remain commonly used. These include: In technology (especially computing), backward compatibility has several related but differing meanings: A system is backward compatible if it is compatible with earlier versions of itself, or sometimes other earlier systems, particularly systems it intends to supplant. ...

• Unified Thread Standard, (UTS), which is still in common use in the United States and Canada. This standard includes:
  • Unified Coarse (UNC)
  • Unified Fine (UNF)
  • Unified Extra Fine (UNEF)
  • Unified Special (UNS)
  • National pipe thread (NPT)

• British Standard Whitworth (BSW), and for other Whitworth threads including:
  • British Standard Fine (BSF)
  • Cycle Engineers' Institute (CEI)
  • British standard pipe thread (BSP)
• British Association screw threads (BA)

• Camera case screws, used to mount a camera on a photographic tripod:
  • ¼″ British Standard Whitworth (BSW) used on almost all small cameras
  • ⅜″ BSW for larger (and some older small) cameras
• British Association screw threads (BA), used in moving coil meters and to mount optical lenses
• Royal Microscopical Society (RMS) thread, a special 0.8"-36 thread used for microscope objective lenses.
• Microphone stands:
  • ⅝″ 27 turns per inch (tpi) Unified Special thread (UNS, USA and the rest of the world)
  • ¼″ BSW (not common in the USA, used in the rest of the world)
  • ⅜″ BSW (not common in the USA, used in the rest of the world)
• Stage lighting suspension bolts (in some countries only; some have gone entirely metric, others such as Australia have reverted to the BSW threads, or have never fully converted):
  • ⅜″ BSW for lighter luminaries
  • ½″ BSW for heavier luminaries
• Panzergewinde (Pg) (also: Stahlpanzerrohr-Gewinde) is an old German 80° thread (DIN 40430) that remained in use until 2000 in some electrical installation accessories in Germany.

The Unified Thread Standard (UTS) specifies the standard thread form, series, class, allowance, tolerance, and designation for unified screw threads. ... Threaded pipe and elbow National pipe thread (NPT) is a U.S. standard for tapered threads used around the world to join pipe and fittings. ... British Standard Whitworth (BSW) is one of three imperial unit based screw thread standards which use the same bolt heads and nut sizes, the other two being British Standard Fine (BSF) and Cycle Engineers Institute (CEI). ... The British standard pipe thread (BSP thread) is a family of standard screw thread types that has been adopted internationally for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread. ... British Association or BA screw threads are a largely obsolete set of small screw threads, the largest being 0BA at 6mm diameter. ... A camera is a device used to take pictures (usually photographs), either singly or in sequence, with or without sound recording, such as with video cameras. ... A tripod, in the context of photography, is a three-legged stand for a camera, used to stabilize and elevate the camera. ... British Standard Whitworth (BSW) is one of three imperial unit based screw thread standards which use the same bolt heads and nut sizes, the other two being British Standard Fine (BSF) and Cycle Engineers Institute (CEI). ... British Association or BA screw threads are a largely obsolete set of small screw threads, the largest being 0BA at 6mm diameter. ... A moving coil meter is used to measure the rate of flow of current in a direct-current circuit. ... Several objective lenses on a microscope. ... A microphone, sometimes referred to as a mike or mic (both IPA pronunciation: ), is an acoustic to electric transducer that converts sound into an electrical signal. ... Turns per inch, abbreviated tpi, is a largely obsolete measure of thread pitch. ... The Unified Thread Standard (UTS) specifies the standard thread form, series, class, allowance, tolerance, and designation for unified screw threads. ... Classical Spectacular used ordinary stage lighting plus special laser effects In the 2005 Classical Spectacular performance, a state of the art lighting system designed by Durham Marenghi was used to accompany the music Starry lighting such as is shown on the RHS of this photo are much more interesting than...

Engineering drawing

In American engineering drawings, ANSI Y14.6 defines standards for indicating threaded parts. Parts are indicated by their nominal diameter (the nominal outside diameter of the screw threads), number of threads per inch, and the class of the thread. For example, “.750-10UNC-2A” is male (A) with a nominal outside diameter of 0.750″, and 10 threads per inch; “.500-20UNC-1B” would be female (B) with a 0.500″ nominal diameter (i.e., the hole will be drilled less than that) and 20 threads per inch. An arrow points from this designation to the surface in question.^[1] It has been suggested that this article or section be merged into Technical drawing. ...

Manufacturing screw threads

Screw threads are normally manufactured by one of three methods:

• Cutting: The excess material is removed, with taps and dies for smaller diameters, or with a thread-cutting lathe for larger ones.

• Rolling: The material is extruded into a thread through mechanical pressure. Common for high-production threads of diameters typically smaller than one inch. A rolled thread is instantly recognizable because the thread has a larger diameter than the blank rod from which it has been made. The threads of bicycle spokes provide a perfect example.

• Casting: Material is either heated to a liquid (or rarely a gas), or dissolved in a liquid that will evaporate and allow the material to solidify (such as plaster or cement). Alternately, the material may be forced into a mould as a powder and compressed into a solid, as with graphite.

Taps and dies are metalworking tools for the creation (cutting) of screw threads in metal parts. ... Conventional metalworking lathe See also: Lathe (tool) A metal lathe is a rigid machine tool designed to remove material from a workpiece, through the action of a cutting tool. ... profile rolling (to manufacture a cone) Rolling is a fabricating process in which the metal, plastic, paper, glass, etc. ... Mid-19th century tool for converting between different standards of the inch An inch is an Imperial and U.S. customary unit of length. ... This racing bicycle is built using lightweight, shaped aluminium tubing and carbon fiber stays and forks. ... A spoke is one of some number of rods radiating from the center of a wheel (the hub where the axle connects), connecting the hub with the round traction surface. ... DC plasma (violet) enhances the growth of carbon nanotubes in this laboratory-scale PECVD apparatus. ... One half of a bronze mould for casting a socketed spear head dated to the period 1400-1000 BC. There are no known parallels for this mould. ... Graphite (named by Abraham Gottlob Werner in 1789 from the Greek γραφειν: to draw/write, for its use in pencils) is one of the allotropes of carbon. ...

Examples

Examples of screw threads include:

• Fasteners:
  • Wood screws.
  • Nuts and bolts, machine screws, cap screws.
• C-clamps.
• Threaded pipe fittings.
• Threaded attachments used to mount equipment on stands, such as:
  • The case screw used to mount a camera on a photographic tripod.
  • The thread used to mount a microphone or microphone cradle on a microphone stand.

See also: Archimedes' screw

A nut is a type of hardware fastener with a threaded hole. ... A bolt may be one of the following things: For bolts and capscrews, see Bolted joint. ... Screws come in a variety of shapes and sizes for different purposes. ... Bolted joints Bolted joints are one of the most common elements in construction and machine design. ... A threaded pipe plug; note that the threaded portion is slightly conical and so touches the calipers at only two points. ... A camera is a device used to take pictures (usually photographs), either singly or in sequence, with or without sound recording, such as with video cameras. ... A tripod, in the context of photography, is a three-legged stand for a camera, used to stabilize and elevate the camera. ... A microphone, sometimes referred to as a mike or mic (both IPA pronunciation: ), is an acoustic to electric transducer that converts sound into an electrical signal. ... All the advances in recording and sound reinforcement still depend on the lowly microphone stand to hold things together. ... Archimedes screw, Archimedean screw, or screwpump, is a machine historically used for transferring water from a low-lying body of water into irrigation ditches. ...

See also

See especially screw for more on standard machine screw threads and their history and on screw threads generally. See also: Screws come in a variety of shapes and sizes for different purposes. ...

• USS or United States Standard
• National Thread Form
• Acme Thread Form
• Buttress Thread Form
• National Pipe Thread Form
• Dryseal Pipe Threads Form
• Hose Coupling Screw Thread Form
• Metric: M Profile Thread Form
• Metric: MJ Profile Thread Form
• Joseph Whitworth
• British Association screw threads (BA)

USS is a three-letter acronym, or TLA that may designate one of the following: United States Ship Typically as a ship prefix in the United States Navy United Star Ship (conjectural) (Star Trek) United States Standard, an older standard of screw thread Uncorrected sum of squares Under-seat steering... Threads formed around a shaft are used to translate rotational motion into linear motion. ... Threaded pipe and elbow National Pipe Thread is a U.S. standard for tapered (NPT) or straight (NPS) threads used to join pipe and fittings. ... Sir Joseph Whitworth Sir Joseph Whitworth, Baronet (December 21, 1803 - January 22, 1887) was an English engineer and entrepreneur. ... British Association or BA screw threads are a largely obsolete set of small screw threads, the largest being 0BA at 6mm diameter. ...

References

1. ^ Wilson, Bruce A. (2004). Design Dimensioning and Tolerancing, 4th ed., Goodheart-Wilcox. ISBN 1-59070-328-6. pp. 77–78 (page numbers may be from an earlier edition).

External links

• [1] www.tapdie.com shows all different types and sizes of drills

International Thread Standards