Screw thread in the context of Deformation (engineering)

Edison screw (ES) is a standard lightbulb socket for electric light bulbs. It was developed by Thomas Edison (1847–1931), patented in 1881, and was licensed in 1909 under General Electric's Mazda trademark. The bulbs have right-hand threaded metal bases (caps) which screw into matching threaded sockets (lamp holders). For bulbs powered by AC current, the thread is generally connected to neutral and the contact on the bottom tip of the base is connected to the "live" phase.

In North America and continental Europe, Edison screws displaced other socket types for general lighting. In the early days of electrification, Edison screws were the only standard connector, and appliances other than light bulbs were connected to AC power via lamp sockets. Today Edison screw sockets comply with international standards.

In manufacturing, threading is the process of creating a screw thread. More screw threads are produced each year than any other machine element. There are many methods of generating threads, including subtractive methods (many kinds of thread cutting and grinding, as detailed below); deformative or transformative methods (rolling and forming; molding and casting); additive methods (such as 3D printing); or combinations thereof.

A screw-propelled vehicle is a land or amphibious vehicle designed to traverse difficult terrain, such as snow, ice, mud, and swamp. Such vehicles are distinguished by being moved by the rotation of one or more auger-like cylinders fitted with a helical flange that engages with the medium through or over which the vehicle is moving. They have been called Archimedes screw vehicles by the US military, where they are classified as a type of marginal terrain vehicle (MTV). Modern vehicles called Amphirols and other similar vehicles have specialised uses.

The weight of the vehicle is typically borne by one or more pairs of large flanged cylinders; sometimes a single flanged cylinder is used with additional stabilising skis. These cylinders each have a helical spiral flange like the thread of a screw. On each matched pair of cylinders, one will have its flange running clockwise and the other counter-clockwise. The flange engages with the surface on which the vehicle rests. Ideally this should be slightly soft material such as snow, sand or mud so that the flange can get a good bite. An engine is used to counter-rotate the cylinders—one cylinder turns clockwise and the other counter-clockwise. The counter-rotations cancel out so that the vehicle moves forwards (or backwards) along the axis of rotation.

The Butterfly Bomb (or Sprengbombe Dickwandig 2 kg or SD 2) was a German 2-kilogram (4.4 lb) anti-personnel submunition (or bomblet) used by the Luftwaffe during the Second World War. It was so named because the thin cylindrical metal outer shell which hinged open when the bomblet deployed gave it the superficial appearance of a large butterfly. The design was very distinctive and easy to recognise. SD 2 bomblets were not dropped individually, but were packed into containers holding between 6 and 108 submunitions e.g. the AB 23 SD 2 and AB 250-3 submunition dispensers. The SD 2 submunitions were released after the container was released from the aircraft and had burst open. Because SD 2s were always dropped in groups (never individually) the discovery of one unexploded SD 2 was a reliable indication that others had been dropped nearby. This bomb type was one of the first cluster bombs ever used in combat and it proved to be a highly effective weapon. The bomb containers that carried the SD 2 bomblets and released them in the air were nicknamed the "Devil's Eggs" by Luftwaffe air and ground crew.

A jack is a mechanical lifting device used to apply great forces or lift heavy loads. A mechanical jack employs a screw thread for lifting heavy equipment. A hydraulic jack uses hydraulic power. The most common form is a car jack, floor jack or garage jack, which lifts vehicles so that maintenance can be performed. Jacks are usually rated for a maximum lifting capacity (for example, 1.5 tons or 3 tons). Industrial jacks can be rated for many tons of load.

The screw is a mechanism that converts rotational motion to linear motion, and a torque (rotational force) to a linear force. It is one of the six classical simple machines. The most common form consists of a cylindrical shaft with helical grooves or ridges called threads around the outside. The screw passes through a hole in another object or medium, with threads on the inside of the hole that mesh with the screw's threads. When the shaft of the screw is rotated relative to the stationary threads, the screw moves along its axis relative to the medium surrounding it; for example rotating a wood screw forces it into wood. In screw mechanisms, either the screw shaft can rotate through a threaded hole in a stationary object, or a threaded collar such as a nut can rotate around a stationary screw shaft. Geometrically, a screw can be viewed as a narrow inclined plane wrapped around a cylinder.

Like the other simple machines a screw can amplify force; a small rotational force (torque) on the shaft can exert a large axial force on a load. The smaller the pitch (the distance between the screw's threads), the greater the mechanical advantage (the ratio of output to input force). Screws are widely used in threaded fasteners to hold objects together, and in devices such as screw tops for containers, vises, screw jacks and screw presses.

A sucker rod is a steel rod, typically measuring between 7 and 9 metres (25 and 30 ft) in length, with threaded ends at both sides. It is used in the oil industry to connect the surface components with the downhole components of a reciprocating piston pump in an oil well. The pumpjack, which is the visible above-ground drive for the well pump, is linked to the downhole pump at the base of the well through a series of interconnected sucker rods. Sucker rods are also available in fiberglass, typically manufactured in lengths of 37 1/2 feet and diameters of 3/4, 7/8, 1, and 1 1/4 inch. These rods feature metallic threaded ends, female on one side and male on the other.

The surface unit transfers energy from the prime-mover to the sucker rod string to facilitate well pumping. It achieves this by converting the rotary motion of the prime-mover into the reciprocating motion required by the sucker rod and reducing the prime-mover's speed to a suitable pumping rate. Speed reduction is managed through a gear reducer, while the rotary motion of the crankshaft is transformed into oscillatory motion using a walking beam. The crank arm connects to the walking beam via a pitman arm. The walking beam is supported by a Samson post and saddle bearing. The horse head and bridle ensure vertical pull on the sucker rod string at all times, preventing bearing movement above the stuffing box. A combination of the polished rod and stuffing box is employed to maintain an effective liquid seal at the surface.

A worm drive is a gear arrangement in which a worm (which is a gear in the form of a screw) meshes with a worm wheel (which is similar in appearance to a spur gear). Its main purpose is to translate the motion of two perpendicular axes or to translate circular motion to linear motion (example: band type hose clamp).The two elements are also called the worm screw and worm gear. The terminology is often confused by imprecise use of the term worm gear to refer to the worm, the worm wheel, or the worm drive as a unit.

The worm drive or "endless screw" was invented by either Archytas of Tarentum, Apollonius of Perga, or Archimedes, the last one being the most probable author. The worm drive later appeared in the Indian subcontinent, for use in roller cotton gins, during the Delhi Sultanate in the thirteenth or fourteenth centuries.

A universal lathe or parallel lathe is the most common type of lathe. It differs from other types of lathes in that it has the option of a tailstock, separate mechanisms for longitudinal and transverse feeds (typically via separate handwheels), and an automatic (usually mechanically) driven longitudinal leadscrew for making threads.

A spark plug (sometimes, in British English, a sparking plug, and, colloquially, a plug) is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine. A spark plug has a metal threaded shell, electrically isolated from a central electrode by a ceramic insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto. The spark plug's metal shell is screwed into the engine's cylinder head and thus electrically grounded. The central electrode protrudes through the porcelain insulator into the combustion chamber, forming one or more spark gaps between the inner end of the central electrode and usually one or more protuberances or structures attached to the inner end of the threaded shell and designated the side, earth, or ground electrode(s).

Spark plugs may also be used for other purposes; in Saab Direct Ignition when they are not firing, spark plugs are used to measure ionization in the cylinders – this ionic current measurement is used to replace the ordinary cam phase sensor, knock sensor and misfire measurement function. Spark plugs may also be used in other applications such as furnaces wherein a combustible fuel/air mixture must be ignited. In this case, they are sometimes referred to as flame igniters.

Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (sinister) and "right" (dexter). Other disciplines use different terms (such as dextro- and laevo-rotary in chemistry, or clockwise and anticlockwise in physics) or simply use left and right (as in anatomy).

Relative direction and chirality are distinct concepts. Relative direction is from the point of view of the observer; a completely symmetric object has a left side and a right side, from the observer's point of view, if the top and bottom and direction of observation are defined. Chirality, however, is observer-independent: no matter how one looks at a right-hand screw thread, it remains different from a left-hand screw thread. Therefore, a symmetric object has sinistral and dextral directions arbitrarily defined by the position of the observer, while an asymmetric object that shows chirality may have sinistral and dextral directions defined by characteristics of the object, regardless of the position of the observer.

An impact sprinkler (sometimes called an impulse sprinkler) is a type of irrigation sprinkler in which the sprinkler head, driven in a circular motion by the force of the outgoing water, pivots on a bearing on top of its threaded attachment nut. Invented in 1933 by Orton Englehart, it quickly found widespread use. Though it has in many situations been replaced by gear-driven "rotor heads", many varieties of impact sprinkler remain in use.

Harvey Hubbell II (born 1857, Connecticut) was an American inventor, entrepreneur, and industrialist. His best-known inventions are the U.S. electrical plug and the pull-chain light socket.

In 1888, at the age of 31, Hubbell quit his job as a manager of a manufacturing company and founded Hubbell Incorporated in Bridgeport, Connecticut, a company which is still in business today, still headquartered near Bridgeport. Hubbell began manufacturing consumer products and, by necessity, inventing manufacturing equipment for his factory. Some of the equipment he designed included automatic tapping machines and progressive dies for blanking and stamping. One of his most important industrial inventions, still in use today, is the thread rolling machine. He quickly began selling his newly devised manufacturing equipment alongside his commercial products.

The bottom bracket on a bicycle connects the crankset (chainset) to the bicycle and allows the crankset to rotate freely. It contains a spindle to which the crankset attaches, and the bearings that allow the spindle and crankset to rotate. The chainrings and pedals attach to the cranks. Bottom bracket bearings fit inside the bottom bracket shell, which connects the seat tube, down tube and chain stays as part of the bicycle frame.

The term "bracket" refers to the tube fittings that are used to hold frame tubes together in lugged steel frames which also form the shell that contains the spindle and bearings; the term is now used for all frames, bracketed or not.

A nut is a type of fastener with a threaded hole. Nuts are almost always used in conjunction with a mating bolt to fasten multiple parts together. The two partners are kept together by a combination of their threads' friction with slight elastic deformation, a slight stretching of the bolt, and compression of the parts to be held together.

In applications where vibration or rotation may work a nut loose, various locking mechanisms may be employed: lock washers, jam nuts, eccentric double nuts, specialist adhesive thread-locking fluid such as Loctite, safety pins (split pins) or lockwire in conjunction with castellated nuts, nylon inserts (nyloc nut), or slightly oval-shaped threads.

A leadscrew (or lead screw), pronounced /liːd skruː/, also known as a power screw or translation screw, is a screw used as a linkage in a machine, to translate turning motion into linear motion. Because of the large area of sliding contact between their male and female members, screw threads have larger frictional energy losses compared to other linkages. They are not typically used to carry high power, but more for intermittent use in low power actuator and positioner mechanisms. Leadscrews are commonly used in linear actuators, machine slides (such as in machine tools), vises, presses, and jacks. Leadscrews are a common component in electric linear actuators.

The word "lead" – pronounced /liːd/, from the verb "to lead" – refers to the amount of distance travelled per rotation, not the metal.

Below is a comprehensive drill and tap size chart for all drills and taps: Inch, imperial, and metric, up to 36.5 millimetres (1.44 in) in diameter.

In manufactured parts, holes with female screw threads are often needed; they accept male screws to facilitate the building and fastening of a finished assembly. One of the most common ways to produce such threaded holes is to drill a hole of appropriate size with a drill bit and then tap it with a tap. Each standard size of female screw thread has one or several corresponding drill bit sizes that are within the range of appropriate size—slightly larger than the minor diameter of the mating male thread, but smaller than its pitch and major diameters. Such an appropriately sized drill is called a tap drill for that size of thread, because it is a correct drill to be followed by the tap. Many thread sizes have several possible tap drills, because they yield threads of varying thread depth between 50% and 100%. Usually thread depths of 60% to 75% are desired.

A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eye bolts, one screwed into each end of a small metal frame, one with a conventional right-hand thread and the other with a left-hand thread. The tension can be adjusted by rotating the frame, which causes both eye bolts to be screwed in or out simultaneously, without twisting the eye bolts or attached cables.