What are screws most commonly made of?
Screw
A screw is a type of fastener, in some ways 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). 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. There are many screws for a variety of materials; those commonly fastened by screws include wood, sheet metal, and plastic.
Strap wrench
The strap or chain can have various forms. Some straps are made of polymers, and are smooth, highly flexible, non-marring, high-friction straps. (Before the era of commercial polymers, the straps were of leather or rubber.) Other straps are bands of spring steel, moderately flexible, slightly firmer and more likely to mar than the polymer variants. The chains tend to be of the roller chain type (like a bicycle chain).
Ice screw
An older type of screw that is rarely used today is a pound-in ice screw, such as the 'snarg' and the 'warthog'. Instead of screwing these into the ice one would pound them in with a hammer from the ice tool, and then screw them out with the pick of an ice axe. The pound-ins have been largely replaced by modern tubular ice screws that are stronger and easier to use, although warthogs are being manufactured in Britain again for use in creating an anchor in frozen turf when no alternative anchor or placement is available, although it is now recommended only as 'marginal' equipment for when no other CE-tested equipment can be placed.
Screw (simple machine)
This self-locking property is one reason for the very large use of the screw in threaded fasteners such as wood screws, sheet metal screws, studs and bolts. Tightening the fastener by turning it puts compression force on the materials or parts being fastened together, but no amount of force from the parts will cause the screw to untighten. This property is also the basis for the use of screws in screw top container lids, vises, C-clamps, and screw jacks. A heavy object can be raised by turning the jack shaft, but when the shaft is released it will stay at whatever height it is raised to.
Archery
The arrowhead is the primary functional component of the arrow. Some arrows may simply use a sharpened tip of the solid shaft, but separate arrowheads are far more common, usually made from metal, stone, or other hard materials. The most commonly used forms are target points, field points, and broadheads, although there are also other types, such as bodkin, judo, and blunt heads.
Fletching is traditionally made from bird feathers, but solid plastic vanes and thin sheet-like spin vanes are used. They are attached near the nock (rear) end of the arrow with thin double sided tape, glue, or, traditionally, sinew. The most common configuration in all cultures is three fletches, though as many as six have been used. Two makes the arrow unstable in flight. When the arrow is "three-fletched", the fletches are equally spaced around the shaft, with one placed such that it is perpendicular to the bow when nocked on the string, though variations are seen with modern equipment, especially when using the modern spin vanes. This fletch is called the "index fletch" or "cock feather" (also known as "the odd vane out" or "the nocking vane"), and the others are sometimes called the "hen feathers". Commonly, the cock feather is of a different color. However, if archers are using fletching made of feather or similar material, they may use same color vanes, as different dyes can give varying stiffness to vanes, resulting in less precision. When an arrow is "four-fletched", two opposing fletches are often cock feathers, and occasionally the fletches are not evenly spaced.
Fork end
Some rear, horizontal, forward-facing dropouts have small adjustment screws threaded through the very rear to aid in positioning the axle precisely. The screws may be fitted with springs to keep them from moving. 
The most common screw size for the adjustment screws is M3.
DC motor
Brushes are usually made of graphite or carbon, sometimes with added dispersed copper to improve conductivity. In use, the soft brush material wears to fit the diameter of the commutator, and continues to wear. A brush holder has a spring to maintain pressure on the brush as it shortens. For brushes intended to carry more than an ampere or two, a flying lead will be molded into the brush and connected to the motor terminals. Very small brushes may rely on sliding contact with a metal brush holder to carry current into the brush, or may rely on a contact spring pressing on the end of the brush. The brushes in very small, short-lived motors, such as are used in toys, may be made of a folded strip of metal that contacts the commutator.
Screw thread
A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a "straight" thread and the latter called a "tapered" thread. A screw thread is the essential feature of the screw as a simple machine and also as a fastener.
Leadscrew
A leadscrew (or lead screw), 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. Common applications are linear actuators, machine slides (such as in machine tools), vises, presses, and jacks.
Dewatering screw press
The most commonly known screw press of this design is said to have been invented by famous Greek mathematician Archimedes and is known as the screw conveyor. The screw conveyor consists of a shaft, which is surrounded by a spiral steel plate, similar in design and appearance to a corkscrew. This design is used in a multitude of screw presses. There are some machines of this and also of similar design that are not screw presses at all - they do not separate solids from liquids but are instead used to fuse them together. An example of this is a mold-filling machine. Plastic pellets are inserted at one end and heat is applied, melting the pellets and discharging them into a mold. Another example is known as a cooker-extruder and is used in the production of snack foods such as pretzels and more.
Screw
British Association (BA) screw threads, named after the British Association for Advancement of Science, were devised in 1884 and standardised in 1903. Screws were described as "2BA", "4BA" etc., the odd numbers being rarely used, except in equipment made prior to the 1970s for telephone exchanges in the UK. This equipment made extensive use of odd-numbered BA screws, in order—it may be suspected—to reduce theft. BA threads are specified by British Standard BS 93:1951 "Specification for British Association (B.A.) screw threads with tolerances for sizes 0 B.A. to 16 B.A."
List of screw drives
An external Torx screw has a projecting head in the shape of a Torx screwdriver bit (instead of a standard recessed cavity); a Torx socket is used to drive it. The external "E" Torx nominal sizing does not correspond to the "T" size (for example, an E40 socket is too large to fit a T40, while an E8 Torx socket will fit a T40 Torx bit). These screws are most commonly encountered in the motor industry.
Strut channel
A strut is usually formed from a metal sheet, folded over into an open channel shape with inwards-curving lips to provide additional stiffness and as a location to mount interconnecting components. Increasingly, struts are being constructed from fiberglass, a highly corrosion-resistant material that's known for its lightweight strength and rigidity. Struts usually have holes of some sort in the base, to facilitate interconnection or fastening strut to underlying building structures.
Leadscrew
Square threads are named after their square geometry. They are the most efficient, having the least friction, so they are often used for screws that carry high power. But they are also the most difficult to machine, and are thus the most expensive.
Cue stick
The heavy, lower piece of the cue is the cue butt, and the smaller, narrower end is the shaft. The two cue pieces are attached at the joint; normally a screw rising from butt end's joint (male) is threaded into a receptacle on the shaft (female), or vice versa. The joints are made of various materials, most frequently a plastic, brass, stainless steel, or wood outer layer, but some custom cues are made of bone, antlers, or other more expensive materials that are less common, but serve the same effect. Most snooker cues have brass-to-brass joints. The internal male and female connection points are almost always brass or steel because they respond less to temperature changes and thus expand and contract less than other materials, preserving the life of the cue. Joints have different sizes as well as different male and female ends on the shaft and butts of the cues. Traditional designs employ a fully threaded connection, while newer versions (marketed under such names as Uni-loc, Accu-loc, Speed-loc, and Tru-loc) employ half-threaded "quick pin release" connections that allow players to assemble and disassemble their cues faster.
Screw
Modern screws employ a wide variety of drive designs, each requiring a different kind of tool to drive in or extract them. The most common screw drives are the slotted and Phillips in the US; hex, Robertson, and Torx are also common in some applications, and Pozidriv has almost completely replaced Phillips in Europe. Some types of drive are intended for automatic assembly in mass-production of such items as automobiles. More exotic screw drive types may be used in situations where tampering is undesirable, such as in electronic appliances that should not be serviced by the home repair person.
Screwdriver
The screwdriver depended entirely on the screw, and it took several advances to make the screw easy enough to produce to become popular and widespread. The most popular door hinge at the time was the butt-hinge, but it was considered a luxury. The butt-hinge was handmade, and its constant motion required the security of a screw.
Screw thread
In ball screws, the male-female pairs have bearing balls in between. Roller screws use conventional thread forms and threaded rollers instead of balls.
Tin whistle
The most common whistles today are made of brass tubing, or nickel plated brass tubing, with a plastic fipple (mouthpiece). Generation, Feadóg, Oak, Acorn, Soodlum's (now Walton's), and other brands fall in this category. The next most common form is the conical sheet metal whistle with a wooden stop in the wide end to form the fipple, the Clarke's brand being the most prevalent. Other less common variants are the all-metal whistle, the PVC whistle, the Flanna square holed whistle, and the wooden whistle.
Splint boots
Modern brushing boots are usually made of synthetic materials such as Neoprene or traditional materials such as leather. They usually attach by a wide velcro fastening which is pulled around the leg, although they can also be pushed through a ring and be fastened back upon themselves, making them more secure and less likely to slip during exercise. They can have between 1 and 5 straps, with front leg boots usually having more straps. Some boots may have buckles, especially older designs. They have a protective padded area on the side of the boot which is on the inside of the horses leg, protecting the cannon bone and fetlock.
Computer case screws
The #6-32 UNC screws are often found on 3.5" hard disk drives and the case's body to secure the covers. The M3 threaded holes are often found on 5.25" optical disc drives, 3.5" floppy drives, and 2.5" drives. Motherboards and other circuit boards often use a #6-32 UNC standoff. #4-40 UNC thumb screws are often found on the ends of DVI, VGA, serial and parallel connectors.
Screw
ASME standard B18.2.1-1996 specifies Hex Cap Screws whose size range is in diameter. These fasteners are very similar to hex bolts. They differ mostly in that they are manufactured to tighter tolerances than the corresponding bolts. "Machinery's Handbook" refers parenthetically to these fasteners as "Finished Hex Bolts". Reasonably, these fasteners might be referred to as bolts, but based on the US government document "Distinguishing Bolts from Screws", the US government might classify them as screws because of the tighter tolerance. In 1991 responding to an influx of counterfeit fasteners Congress passed PL 101-592 "Fastener Quality Act" This resulted in the rewriting of specifications by the ASME B18 committee. B18.2.1 was re-written and as a result they eliminated the "Finished Hex Bolts" and renamed them the "Hex Cap Screw"—a term that had existed in common usage long before, but was now also being codified as an official name for the ASME B18 standard.
Computer case screws
The M3 is a metric screw specifying a nominal diameter of ; and standard coarse thread pitch defined as . The M3 is the second most common screw found in PCs. It commonly appears in many lengths from 1-20mm. Nearly every brand-new computer case comes with a bag of these. Notwithstanding many exceptions, they are commonly used for securing the following devices: however there are many exceptions:
Screw
Lag screws (US) or coach screws (UK, Australia, and New Zealand) (also referred to as lag bolts or coach bolts, although this is a misnomer) are large wood screws. Square-headed and hex-headed lag screws are covered by ASME B18.2.1 standards, and the head is typically an external hex. A typical lag screw can range in diameter from to , and lengths from or longer, with the coarse threads of a wood-screw or sheet-metal-screw threadform (but larger).
Screw extractor
A screw extractor is a tool for removing broken or seized screws. There are two types: one has a spiral flute structure, commonly called an easy out after the trademarked name "EZ-Out"; the other has a straight flute structure. Screw extractors are intentionally made of hard, brittle steel, and, if too much torque is applied, can break off inside the screw that is being removed. Since the extractor is an extremely hard material, and a typical home shop drill bit will not be able to drill into it, a larger element of difficulty is added to the original screw extraction project. One way to avoid this added difficulty is to drill a hole completely through the screw. Thus, if the fastener breaks, a punch can be used to drive out the easy out from the screw, via the back, or end, of the fastener.
Boat building
Silicon bronze screws are normally used in boat building but can be hard to locate. Brass fasteners are commonly available but apart from being softer and weaker the common brass alloys are much more prone to corrosion through depletion of their zinc content. Stainless steel screws may be used for attaching fittings to the hull above the water line. Type 316 stainless steel is the only stainless steel recommended. Even 316 may get stained with surface rust but this does not penetrate the surface. Staining comes from being in contact with other steels such as the anchor or incorrect cleaning in the factory. Staining near wields should be removed as it can pit. Experienced boat builders are reluctant to use even 316 below the water line in a boat permanently in salt water. This especially applied to long thin fastenings such as screws in boats that have motors. Sacrificial anodes are used to help prevent corrosion underwater but experts will inspect a sample of long thin screws or bolts annually to check for corrosion.
Screw
The international standards for metric externally threaded fasteners are ISO 898-1 for property classes produced from carbon steels and ISO 3506-1 for property classes produced from corrosion resistant steels. Some varieties of screw are manufactured with a break-away head, which snaps off when adequate torque is applied. This prevents tampering and also provides an easily inspectable joint to guarantee proper assembly. An example of this is the shear bolts used on vehicle steering columns, to secure the ignition switch.
Drum hardware
There are a number of components that make up a drum's anatomy. Some of these anatomical components vary dependent upon the type of drum, the manufacturer, and the year in which it was made. However, nearly all modern drums have the same essential components. Kick drums often have legs called "spurs" on either side of the drum shell. These spurs are used to prevent the kick drum from rolling side to side, to prevent the drum from sliding forward as it is being played and to provide overall added stability to the drum. Casings, also known as lugs, vary in shape and size. They all serve the same purpose as the receiving end of the drum tension rod (also known as a tuning screw) and provide the anchor point for the tension rods themselves. Casings are found on nearly all modern drums. The number of casings a drum has can vary from drum to drum and manufacturer to manufacturer. A drum can have as little as six casings and as many as twelve. Tension rods, also known as tuning screws, are threaded bolts that are placed around the rim of a drum and screw into the casings. They enable the musician to adjust the tension of the drum's head and affect its overall pitch, tone, and timbre. They come in many lengths and should also always have a tension rod washer that is often made of metal or hard plastic.
Screw
ASME standards specify a variety of "Machine Screws" in diameters ranging up to . These fasteners are often used with nuts but also often driven into tapped holes (without nuts). They might be considered a screw or a bolt based on the "Machinery's Handbook" distinction. In practice, they tend to be mostly available in smaller sizes and the smaller sizes are referred to as screws or less ambiguously as machine screws, although some kinds of machine screw can be referred to as stove bolts.
List of screw drives
A U-drive screw has a helical thread with an angle acute enough to be driven by a hammer, and thus has a domed head with no means of turning it. These are most frequently driven into plastic.
Unified Thread Standard
The number series of machine screws has been extended downward to include #00-90 (0.047 in = 0.060 in − 0.013 in) and #000-120 (0.034 in = 0.060 in − 2 × 0.013 in) screws; however, the main standard for screws smaller than #0 is ANSI/ASME standard B1.10 Unified Miniature Screw Threads. This defines a series of metric screws named after their major diameters in millimetres, from 0.30 UNM to 1.40 UNM. Preferred sizes are 0.3, 0.4, 0.5, 0.6, 0.8, 1.0 and 1.2 mm, with additional defined sizes halfway between. The standard thread pitch is approximately of the major diameter. The thread form is slightly modified to increase the minor diameter, and thus the strength of screws and taps. The major diameter still extends to within "H" of the theoretical sharp "V", but the total depth of the thread is reduced 4% from "H" =  cos(30°) "P" ≈ 0.541"P" to 0.52"P". This increases the amount of the theoretical sharp "V" which is cut off at the minor diameter by 10% from 0.25"H" to − ≈ 0.27456"H".
Screw
Earlier, the screw had been described by the Greek mathematician Archytas of Tarentum (428–350 BC). By the 1st century BC, wooden screws were commonly used throughout the Mediterranean world in screw presses for pressing olive oil from olives and pressing juice from grapes in winemaking. Metal screws used as fasteners were rare in Europe before the 15th century, if known at all.
Computer case screws
Steel is by far the most common material used, frequently with a plated or anodized finish. Other materials including brass, aluminum, nylon and various plastics are also used for applications with particular physical or aesthetic requirements.
Wrench
In North American English, "wrench" is the standard term. The most common shapes are called "open-end wrench" and "box-end wrench". In American English, "spanner" refers to a specialised wrench with a series of pins or tabs around the circumference. (These pins or tabs fit into the holes or notches cut into the object to be turned.) In American commerce, such a wrench may be called a "spanner wrench" to distinguish it from the British sense of "spanner".
Set screw
Common points include the following:
Screwdriver
Gunsmiths still call a screwdriver a "turnscrew", under which name it is an important part of a set of pistols. The name was common in earlier centuries, used by cabinetmakers, shipwrights, and perhaps other trades. The cabinetmaker's screwdriver is one of the longest-established handle forms, somewhat oval or ellipsoid in cross section. This is variously attributed to improving grip or preventing the tool rolling off the bench. The shape has been popular for a couple of hundred years. It is usually associated with a plain head for slotted screws, but has been used with many head forms. Modern plastic screwdrivers use a handle with a roughly hexagonal cross section to achieve these same two goals, a far cry from the pear-shaped handle of the original 15th-century screwdriver.
Plate nut
A plate nut, also known as a nut plate, anchor nut or anchor plate, is a stamped sheet metal nut that is usually riveted to a workpiece. They have a long tube that is internally threaded and a plate with two clearance holes for rivets. The most popular versions have two lugs and they exist as fixed anchor nuts and as floating anchor nuts. The latter allows the nut to move slightly and so enlarges the positioning tolerances of the mounted parts. They were originally developed for the aerospace industry, but are now also common in automotive racing.
These nuts are made up of variety of soft and hard materials. The choice of material depends on environment to which nut is subjected. Soft materials like copper or brass are used when nut is used in electrical application. Hard materials are used when nut is subjected to high stress environment. Sometimes stainless steel or nickel-plated nuts are used in order to increase corrosion resistance.
Alternative wine closure
Screw caps or "Stelvin caps" are closures made only from aluminium material that threads onto the bottleneck. They are the predominant closure used by Austrian, Australian and New Zealand wineries. This can be attributed in part to the New Zealand screw cap initiative which promotes the use of screw caps instead of cork. Screw caps form a tighter seal and can keep out oxygen for a longer time than cork. These benefits aid in maintaining the wine's overall quality and aging potential. Michel Laroche of Domaine Laroche noted that this played a role in his decision to adopt screwcaps. "Extensive quality tests show convincing results: apart from protecting against cork taint, screwcaps are also beneficial in the aging of wine, particularly preserving the aromatic freshness."
Screw
Throughout the 19th century, the most commonly used forms of screw head (that is, drive types) were simple internal-wrenching straight slots and external-wrenching squares and hexagons. These were easy to machine and served most applications adequately. Rybczynski describes a flurry of patents for alternative drive types in the 1860s through 1890s, but explains that these were patented but not manufactured due to the difficulties and expense of doing so at the time. In 1908, Canadian P. L. Robertson was the first to make the internal-wrenching square socket drive a practical reality by developing just the right design (slight taper angles and overall proportions) to allow the head to be stamped easily but successfully, with the metal cold forming as desired rather than being sheared or displaced in unwanted ways. Practical manufacture of the internal-wrenching hexagon drive (hex socket) shortly followed in 1911.
Chain drive
Drive chains are most often made of metal, while belts are often rubber, plastic, urethane, or other substances.
ISO metric screw thread
The ISO metric screw threads are the worldwide most commonly used type of general-purpose screw thread. They were one of the first international standards agreed when the International Organization for Standardization (ISO) was set up in 1947.
Screwdriver
Many modern electrical appliances, if they contain screws, use screws with heads other than the typical slotted or Phillips styles. Torx is one such pattern that has become widespread. It is a spline tip with a corresponding recess in the screw head. The main cause of this trend is manufacturing efficiency: Torx screwdriver tips do not slip out of the fastener as easily as would a Phillips or slotted driver. (Slotted screws are rarely used in mass-produced devices, since the driver is not inherently centered on the fastener.)
Self-tapping screw
Sheet metal screws (sometimes called "sheet-metal self-tappers", or P-K screws from the brand name "Parker Kalon" - who pioneered the manufacture of, but did not invent, these screws) are a type of self-tapping screw despite the thread created in the sheet of metal being small. Pan-head PK Self-tapping screws are common in electrical equipment, while flatter-headed truss or flat countersunk headed self-tapping screws are more common in aviation applications.
Screw
There are many standards governing the material and mechanical properties of imperial sized externally threaded fasteners. Some of the most common consensus standards for grades produced from carbon steels are ASTM A193, ASTM A307, ASTM A354, ASTM F3125, and SAE J429. Some of the most common consensus standards for grades produced from corrosion resistant steels are ASTM F593 & ASTM A193.
Screw
There is no universally accepted distinction between a screw and a bolt. A simple distinction that is often true, although not always, is that a bolt passes through a substrate and takes a nut on the other side, whereas a screw takes no nut because it threads directly into the substrate (a screw "screws into something", a bolt "bolts several things together"). So, as a general rule, when buying a packet of "screws" nuts would not be expected to be included, but bolts are often sold with matching nuts. Part of the confusion over this is likely due to regional or dialectical differences. "Machinery's Handbook" describes the distinction as follows:
Lacrosse stick
Modern handles, more commonly referred to as "shafts," are made of hollow metal. They are usually octagonal, instead of round, in order to provide a better grip. Most are made of aluminum, titanium, scandium, or alloys, but some shafts are still made from other materials, including wood, plastic, or fiberglass. The open end of the hollow shaft must be covered with tape or a plug (commonly referred to as the "butt" or "butt end" of the stick), usually made of rubber. The head of the stick is usually attached to the shaft with a screw to keep it in place.
Screw gun
A screw gun is similar to a power drill, but designed specifically for driving screws. It automatically feeds screws from a clip, similarly to how nail guns feed nails. A screw gun looks like a drill, but has a "nose" instead of a chuck. The nose holds an interchangeable shank bit, commonly known as a tip. The most common type of tip is a #2 phillips. The nose on either type of screw gun can be adjusted to countersink screws to the desired depth. The user must apply pressure to the bit to engage the clutch and drive the screws. Some screw gun users keep the motor running constantly, while installing drywall, and manufacturers recommend this. A decking screw gun has a long handle so the user does not have to bend over.
Fine adjustment screw
The material of choice for producing these screws is stainless steel typically 18-8 (303). At the tip of the screw most commonly a stainless steel ball is either pressed or glued into place to provide a single point contact for the surface being moved. Common usage has shown the glue method of attaching the ball to be troublesome in many applications as some commonly used glues (Super Glue) tend to outgas and degrade over time in this application.
Set screw
Set screws are made with a variety of drive styles, including the following:
Socket wrench
There are two main types of socket wrenches: impact sockets and hand sockets. Common sockets are colloquially referred to by counting the number of "points" (pointed corners of walls) present in the shape of the socket nut opening. For example, the hexagon shape is commonly called a "6 point" socket because the hexagon forms 6 "points" where walls intersect to create six sharp pointed corners. This system of description using "points" generally works well in avoiding confusion, with the exception of "8-point" and "12-point" where two very incompatible shapes exist with both having 8 "points" and 12 "points". The vast majority of larger common nut and bolt heads are produced with the 6-point hexagonal gripping shape. Less frequently used shapes include the square 4-point, triple square 12-point (not to be confused with 12-point double hexagon), octagonal 8-point (not to be confused with the more common 8-point double square shape). These less common shapes are typically found in special applications or particular industries such as aircraft, PVC plumbing fittings or German and UK made automobiles. With rail cars, valve adjustment screws and pipe plugs, the 4-point square shaped driver can still be found in wide use both male and female configurations. Nuts and bolt heads are also produced in 12-point double hexagon shapes and various types of splines, more common to aircraft and aerospace applications. Most manufacturers of sockets for larger bolts produce them in 6-point (hexagonal) and limited sizes of 12-point (double-hexagonal) configurations.
Screw
The first path was pioneered by brothers Job and William Wyatt of Staffordshire, UK, who patented in 1760 a machine that we might today best call a screw machine of an early and prescient sort. It made use of a leadscrew to guide the cutter to produce the desired pitch, and the slot was cut with a rotary file while the main spindle held still (presaging live tools on lathes 250 years later). Not until 1776 did the Wyatt brothers have a wood-screw factory up and running. Their enterprise failed, but new owners soon made it prosper, and in the 1780s they were producing 16,000 screws a day with only 30 employees—the kind of industrial productivity and output volume that would later be characteristic of modern industry but was revolutionary at the time.
Slug (coin)
Slugs are usually made from metals differing from those of real coins. While genuine coins in the United States currency are made from various alloys of copper, nickel, and zinc, Canadian coins are made mostly from steel with some copper and nickel, and euro coins are made from steel, nickel, and brass, slugs are frequently made from differing metals and alloys that are cheaper to obtain and mold, such as aluminum, tin, and lead.
List of screw drives
The American Screw Company of Providence, Rhode Island, was responsible for devising a means of efficiently manufacturing the screw, and successfully patented and licensed their method; other screw makers of the 1930s dismissed the Phillips concept because it called for a relatively complex recessed socket shape in the head of the screw — as distinct from the simple milled slot of a slotted type screw. The Phillips screw design was developed as a direct solution to a number of problems with slotted screws: too-easy cam out; precise alignment required to avoid slippage and damage to driver, fastener, and adjacent surfaces; and difficulty of driving with powered tools.
Screw
These fasteners are "screws" according to the "Machinery's Handbook" criteria, and the obsolescent term "lag bolt" has been replaced by "lag screw" in the "Handbook". However, to many tradesmen, they are "bolts", because they are large, with hex or square heads.
Roller screw
Inverted roller screws operate on the same principles of standard roller screws except that the function of the nut and screw is reversed in relation to the rollers. The rollers move axially within the nut, which is elongated to accommodate the full extent of screw shaft travel. The threaded portion of the screw shaft is limited to the threaded length of the rollers. The non-threaded portion of the screw shaft can be a smooth or non-cylindrical shape. The ring gear is replaced by gear teeth above and below the threaded portion of the screw shaft.
Screw
The materials are usually carbon steel substrate with a coating of zinc galvanization (for corrosion resistance). The zinc coating may be bright (electroplated), yellow (electroplated), or dull gray hot-dip galvanized. Lag screws are used to lag together lumber framing, to lag machinery feet to wood floors, and for other heavy carpentry applications. The attributive modifier "lag" came from an early principal use of such fasteners: the fastening of lags such as barrel staves and other similar parts.
Screw (simple machine)
By common convention, right-handedness is the default handedness for screw threads. Therefore, most threaded parts and fasteners have right-handed threads. One explanation for why right-handed threads became standard is that for a right-handed person, tightening a right-handed screw with a screwdriver is easier than tightening a left-handed screw, because it uses the stronger supinator muscle of the arm rather than the weaker pronator muscle. Since most people are right-handed, right-handed threads became standard on threaded fasteners.
Screw
There were many forms of fastening in use before threaded fasteners became widespread. They tended to involve carpentry and smithing rather than machining, and they involved concepts such as dowels and pins, wedging, mortises and tenons, dovetails, nailing (with or without clenching the nail ends), forge welding, and many kinds of binding with cord made of leather or fiber, using many kinds of knots. Prior to the mid-19th century, cotter pins or pin bolts, and "clinch bolts" (now called rivets), were used in shipbuilding. Glues also existed, although not in the profusion seen today.
Screw
Precision screws, for controlling motion rather than fastening, developed around the turn of the 19th century, were one of the central technical advances, along with flat surfaces, that enabled the industrial revolution. They are key components of micrometers and lathes.
List of screw drives
The triple-square, also known as XZN, is a type of screw drive with 12 equally spaced protrusions, each ending in a 90° internal angle. Common sizes are 6, 8, 10, and 12 mm. The name derives from overlaying three equal squares to form such a pattern with 12 right-angled protrusions (a 12-pointed star). In other words, three Robertson squares are superimposed at a successive 30° rotation. The design is similar to that of the double-square—in both cases, the idea being that it resembles a square (Robertson) but can be engaged at more frequent angles by the driver bit. These screws can be driven with standard Robertson bits.
Set screw
The concept of set screws is centuries old, predating the metal screw by at least several hundred years. Early materials included wood, bone, horn, antler and ivory.
Nut (hardware)
Square nuts, as well as bolt heads, were the first shape made and used to be the most common largely because they were much easier to manufacture, especially by hand. While rare today due to the reasons stated below for the preference of hexagonal nuts, they are occasionally used in some situations when a maximum amount of torque and grip is needed for a given size: the greater length of each side allows a spanner to be applied with a larger surface area and more leverage at the nut.
Edison screw
In countries that use 220–240 volt AC domestic power, standard-size E27 and small E14 are the most common screw-mount sizes and are prevalent throughout continental Europe and China.
Screw
There are many systems for specifying the dimensions of screws, but in much of the world the ISO metric screw thread preferred series has displaced the many older systems. Other relatively common systems include the British Standard Whitworth, BA system (British Association), and the Unified Thread Standard.
Screw (simple machine)
Different shapes (profiles) of threads are used in screws employed for different purposes. Screw threads are standardized so that parts made by different manufacturers will mate correctly.
Screw
The majority of screws are tightened by clockwise rotation, which is termed a "right-hand thread"; a common mnemonic device for remembering this when working with screws or bolts is "righty-tighty, lefty-loosey". If the fingers of the right hand are curled around a right-hand thread, it will move in the direction of the thumb when turned in the same direction as the fingers are curled. Screws with left-hand threads are used in exceptional cases, where loads would tend to loosen a right handed fastener, or when non-interchangeability with right-hand fasteners is required. For example, when the screw will be subject to counterclockwise torque (which would work to undo a right-hand thread), a left-hand-threaded screw would be an appropriate choice. The left side pedal of a bicycle has a left-hand thread.
List of screw drives
Dzus (pronounced "Zeus") screws are similar to Hi-Torque screws, and are typically used in the aviation industry to secure inspection panels and other access doors that need to be opened and closed frequently, but are too small or thin to support other types of latches.
List of screw drives
The TA is a type of screw drive that uses a triangle-shaped recess in the screw head. This drive can restrict access to the device internals but can readily be driven with hex keys. These screws are often found in children's toys from fast food restaurants, as well as vacuum cleaners, fan heaters, elevators, camping stoves, golf clubs, Breville kettles and Master Locks, among others, Sizes include TA14, TA18, TA20, TA23 and TA27. Note that the sides of the triangle are straight, which differs from Tri-point-3 fasteners.
Screw
A screw is a combination of simple machines—it is in essence an inclined plane wrapped around a central shaft, but the inclined plane (thread) also comes to a sharp edge around the outside, which acts a wedge as it pushes into the fastened material, and the shaft and helix also form a wedge in the form of the point. 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 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.
Sgian-dubh
Traditionally the scabbard is made of leather reinforced with wood and fitted with mounts of silver or some other metal which may be cast or engraved with designs ranging from Scottish thistles, Celtic knotwork, or heraldic elements such as a crest. While this makes for more popular and expensive knives, the sheath is hidden from view in the stocking while the is worn. The sheaths of many modern sgian-dubhs are made of plastic mounted with less expensive metal fittings.
Arrow
The shaft is the primary structural element of the arrow, to which the other components are attached. Traditional arrow shafts are made from strong, lightweight wood, bamboo or reeds, while modern shafts may be made from aluminium, carbon fibre reinforced plastic, or a combination of materials. Such shafts are typically made from an aluminium core wrapped with a carbon fibre outer. A traditional premium material is Port Orford Cedar.
Skin (aeronautics)
Sheet assembly of light aircraft is accomplished predominantly with rivets of alloys 2017-T4, 2117-T4, or 2024-T4. Self-tapping sheet metal screws are available in aluminum alloys, but cadmium-plated steel screws are employed more commonly to obtain higher shear strength and driveability. Alloy 2024-T4 with an anodic coating is standard for aluminum screws, bolts, and nuts made to military specifications. Alloy 6262-T9, however, is superior for nuts, because of its virtual immunity to stress-corrosion cracking.
Set screw
Headless set screws have been around for a long time, with the straight slot being the oldest drive type (due to its ease of machining), but the demand for headless set screws experienced a marked increase in the first and second decades of the 20th century, when a penchant for better industrial safety, a campaign with the slogan "safety first", swept the industrialized nations of North America and Europe as a part of the larger Progressive Movement. This surge in safety consciousness was a backlash against the often-atrocious industrial safety standards of the era. H.T. Hallowell, Sr., a U.S. industrialist whose corporation was one of several that pioneered the commercialization of the hex socket drive, noted in his memoir that line shafting, which was ubiquitous in the industrial practice of the time, often had headed set screws (with external-wrenching square drive) holding the many pulleys to the line shafts, and collars holding the shafts from axial movement. Gear trains of exposed gears were also common at the time, and those, too, often used headed set screws, holding the gears to the shafts. His company's chief products at the time were shaft hangers and shaft collars of pressed-steel construction. The "safety craze" created a burgeoning demand for headless set screws on pulleys, gears, and collars to replace the headed ones, so that workers' clothing and fingers were less likely to catch on the exposed rotating screw head. It was this heightened demand that prompted Hallowell's firm to get into the screw-making business and to explore socket-head drive designs. With P.L. Robertson holding fresh patent rights on a practical-to-make square-socket drive, the firm soon pursued the hex socket drive.Fastenere
Screw
The nominal diameter of a metric screw is the outer diameter of the thread. The tapped hole (or nut) into which the screw fits, has an internal diameter which is the size of the screw minus the pitch of the thread. Thus, an M6 screw, which has a pitch of 1 mm, is made by threading a 6 mm shank, and the nut or threaded hole is made by tapping threads into a hole of 5 mm diameter (6 mm - 1 mm).
Computer case screws
They are almost always provided with a #2 Phillips drive. Sometimes a Torx drive is used instead. Both Phillips and Torx patterns may also be combined with a slot for a flat-blade screwdriver. Usually they are provided with a 1/4 in () flanged hex head. Non-standard metricized flanged hex heads can also be encountered. Also common are "pan head" screws - a low disk with a chamfered outer edge. Because they are used in places where high torque is not required and easy removal and replacement may be desirable (such as on the side panels of the PC case), they are frequently available as thumbscrews with larger, knurled heads that can be removed with one's fingers or tools.
Spring (device)
Springs are made from a variety of elastic materials, the most common being spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication. Some non-ferrous metals are also used including phosphor bronze and titanium for parts requiring corrosion resistance and beryllium copper for springs carrying electrical current (because of its low electrical resistance).
List of screw drives
Some screws have heads designed to accommodate more than one kind of driver, sometimes referred to as combo-head or combi-head. The most common of these is a combination of a slotted and Phillips head, often used in attaching knobs to furniture drawer fronts. Because of its prevalence, there are now drivers made specifically for this kind of screw head. Other combinations are a Phillips and Robertson, a Robertson and a slotted, a Torx and a slotted and a triple-drive screw that can take a slotted, Phillips or a Robertson.
Screw-cutting lathe
The earliest screws tended to be made of wood, and they were whittled by hand, with or without the help of turning on a lathe with hand-controlled turning tools (chisels, knives, gouges), as accurately as the whittler could manage. It is likely that sometimes the wood blanks that they started from were tree branches (or juvenile trunks) that had been shaped by a vine wrapped helically around them while they grew. (In fact, various Romance words for "screw" come from the word root referring to vines.) Walking sticks twisted by vines show how suggestive such sticks are of a screw.
Drum kit
Sticks were traditionally made from wood (particularly maple, hickory, and oak) but more recently metal, carbon fibre and other exotic materials have been used for high market end sticks. The prototypical wooden drum stick was primarily designed for use with the snare drum, and optimized for playing snare rudiments. Sticks come in a variety of weights and tip designs; 7N is a common jazz stick with a nylon tip, while a 5B is a common wood tipped stick, heavier than a 7N but with a similar profile, and a common standard for beginners. Numbers range from 1 (heaviest) to 10 (lightest).
Ice climbing
Today the most common protection for ice climbing is an ice screw. Ice screws are hollow tubes with sharp teeth on the front end, a hanger eye at the back to clip into, and threading around the tube. They are screwed into the ice and can provide very strong protection in solid ice. However, because of the variable nature of ice, the strength of ice screw placements can vary greatly.
Screwdriver (cocktail)
A screwdriver is a popular alcoholic highball drink made with orange juice and vodka. While the basic drink is simply the two ingredients, there are many variations; the most common one is made with one part vodka, one part of any kind of orange soda, and one part of orange juice. Many of the variations have different names in different parts of the world. The International Bartenders Association has designated this cocktail as an IBA Official Cocktail.
Screw cap (wine)
A screw cap is a metal cap that screws onto threads on the neck of a wine bottle, generally with a metal skirt down the neck to resemble the traditional wine capsule ("foil"). A layer of plastic (often PVDC), cork, rubber, or other soft material is used as wad to make a seal with the mouth of the bottle. Its use as an alternative wine closure is gaining increasing support as an alternative to cork for sealing wine bottles. In markets such as Australia and New Zealand screw caps on bottles have overtaken cork to become the most common means of sealing bottles.
Shave brush
Modern shave brushes are similar in appearance, composition and function to their centuries-old predecessors. Although a variety of different materials are still used to fashion shave brush handles, synthetic handles of nylon, urethane or plastic are the most common even by the most expensive shave brush manufacturers. Benefits of synthetic handles include a lesser chance of breakage and resistance to damage by moisture. A limited number of consumers prefer natural materials such as wood or exotic materials such as tortoiseshell. A shave brush's handle, regardless of its material composition, rarely affects the overall performance of the brush.
Steel Tec
Unlike Meccano (up until recently), the screws did not use a regular screwdriver, but an allen key. Sometimes the manufacturing tolerances were poor, and the screws were hard to use.
Vandal-resistant switch
Pushbutton vandal-resistant switches are frequently constructed of stainless steel or other durable materials, and are mounted into panels or housing boxes made out of strong materials, such as polycarbonate plastic, aluminium, or stainless steel. In some cases, the housing may be thick, to protect both the switch and the housing from attempts by vandals to damage the switch or housing using blunt force. The housing for vandal-proof switches is often secured using security screws (which cannot be unscrewed with regular screw drivers). The height of buttons in the panel is often minimized by using flush-mounting, to make it more difficult to pry them out, a design technique used in ATM banking machines that are located outside.
List of screw drives
A screw drive is a system used to turn a screw. At a minimum, it is a set of shaped cavities and protrusions on the screw head that allows torque to be applied to it. Usually, it also involves a mating tool, such as a screwdriver, that is used to turn it. The following heads are categorized based on commonality, with some of the less-common drives being classified as "tamper-resistant".
Screw (simple machine)
So the mechanical advantage of an actual screw is reduced from what it would be in an ideal, frictionless screw by the efficiency formula_20. Because of their low efficiency, in powered machinery screws are not often used as linkages to transfer large amounts of power but are more often used in positioners that operate intermittently.
List of screw drives
There are two types of clutch screw drives: Type A and Type G. Type A, also known as a "standard clutch", resembles a bow tie, with a small circular "knot" at the center. These were common in GM automobiles, trucks and buses of the 1940s and 1950s. Type G resembles a butterfly, and lacks the center "knot". This type of screw head is commonly used in the manufacture of mobile homes and recreational vehicles. The clutch head was designed to be driven with a flat-blade screwdriver as well as a clutch driver.
A thumbscrew is a type of screw drive with either a tall head and ridged or knurled sides, or a key-like flat sided vertical head. They are intended to be tightened and loosened by hand, and not found in structural applications. They are sometimes also cut for Phillips head or slotted screwdrivers as well as having the knurl for finger grip. ASME 18.6.8 covers dimensions for Type A (shoulder under the head), regular and heavy, along with Type B (without shoulder), regular and heavy. They can be found on many computer cases, and in other locations where easy access without tools is desired.
Drill bit
Spoon bits consist of a grooved shank with a point shaped somewhat like the bowl of a spoon, with the cutting edge on the end. The more common type is like a gouge bit that ends in a slight point. This is helpful for starting the hole, as it has a center that will not wander or walk. These bits are used by chair-makers for boring or reaming holes in the seats and arms of chairs. Their design is ancient, going back to Roman times. Spoon bits have even been found in Viking excavations. Modern spoon bits are made of hand-forged carbon steel, carefully heat-treated and then hand ground to a fine edge.
Wheelbuilding
Stainless steel is the most common material for spokes, although most mass-produced budget wheels use galvanized steel spokes. Other materials such as titanium or aluminum are often used to reduce weight. Some wheels are designed around carbon fiber spokes, which are often completely integrated with the hub and rim and bladed in shape. Non-steel spokes are normally reserved for racing bikes and other specialist applications where weight, aerodynamics and performance are valued over durability and cost.
Shovel
Most shovels are hand tools consisting of a broad blade fixed to a medium-length handle. Shovel blades are usually made of sheet steel or hard plastics and are very strong. Shovel handles are usually made of wood (especially specific varieties such as ash or maple) or glass-reinforced plastic (fibreglass).
List of screw drives
The line screw drive is a Japanese system with male, female and female tamper-resistant screw configurations. The fasteners are commonly called "line head screws". They are also known as "game bit screws", due to their use on some video game consoles. They are found on IBM computers, as well as Nintendo and Sega systems and their game cartridges. The female sizes are designated ALR2, ALR3, ALR4, ALR5, ALR6; the male sizes are designated with an "H" instead of an "R"; and the tamper-resistant female have a "T" at the end of the designation (e.g. ALR3T).
Dewatering screw press
The buildup of press cake moisture is controlled by a discharge door or cone. Screw presses possess different options that include perforated/slotted screens, a rotating cone, hard surfacing on the screw, and supplemental screen surface in the inlet hopper on the face of the cone. The standard construction for screw presses is of stainless steel with a carbon steel frame on the larger presses.
Archimedes' screw
The design of the everyday Greek and Roman water screw, in contrast to the heavy bronze device of Sennacherib, with its problematic drive chains, has a powerful simplicity. A double or triple helix was built of wood strips (or occasionally bronze sheeting) around a heavy wooden pole. A cylinder was built around the helices using long, narrow boards fastened to their periphery and waterproofed with pitch.
Spyderco
Spyderco's knives are made with a plain edge, a partially serrated edge, or a fully serrated "Spyder Edge" configuration. Their most common handle material is FRN (Fiberglass Reinforced Nylon) and G10, although they make knives with steel handles as well as some limited editions with handles from various other materials.
Screw (simple machine)
A 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.
Screw
In common usage, the distinction (not rigorous) is often that screws are smaller than bolts, and that screws are generally tapered while bolts are not. For example, cylinder head bolts are called "bolts" (at least in North American usage) despite the fact that by some definitions they ought to be called "screws". Their size and their similarity to a bolt that would take a nut seem linguistically to overrule any other factors in this natural word choice proclivity.
Chuck (engineering)
Many chucks have removable jaws (often the top part is removable leaving the base or 'master jaw' assembled with the scroll), which allows the user to replace them with new jaws, specialised jaws, or soft jaws. Soft jaws are made of soft materials such as soft (unhardened) metal, plastic, or wood. They can be machined as needed for particular setups. The typical interface between the master jaw and the removable jaw is a matching pair of serrated surfaces, which, once clamped by the mounting screws, cannot allow relative slipping between the two parts.
Racket (sports equipment)
Standard squash rackets are governed by the rules of the game. Traditionally they were made of laminated timber (typically Ash), with a small strung area using natural gut strings. After a rule change in the mid-1980s, they are now almost always made of composite materials such as carbon fiber or metals (graphite, Kevlar, titanium, and/or boron) with synthetic strings. Modern rackets are 70 cm long, with a maximum strung area of 500 square centimetres (approximately 75 square inches) and a mass between 90 and 200 grams (4–7 ounces).
Computer case screws
The #6-32 UNC is a UTS screw specifying a major thread diameter of which is defined as ; and (threads per inch) which equates to a thread pitch of . The optional UNC specification indicates the standard coarse thread is used which is defined for #6 screws as 32 tpi rendering 'UNC' redundant, however it may be seen when other specifications such as plating or other treatments are also specified. It is by far the most common screw found inside computer cases. It commonly appears in lengths of () and () or less often (). Non-standard metricized lengths such as are also sometimes encountered. Nearly every brand new computer case comes with a bag of these. They are commonly used for the following purposes, however there are many exceptions:
Self-tapping screw
Self-tapping screws have a wide range of tip and thread patterns, and are available with almost any possible screw head design. Common features are the screw thread covering the whole length of the screw from tip to head and a pronounced thread hard enough for the intended substrate, often case-hardened.