Wrench

A wrench or spanner is a tool

Tool

A tool is a device that can be used to produce an item or achieve a task, but that is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tools that are used in particular fields or activities may have different designations such...

 used to provide grip and mechanical advantage

Mechanical advantage

Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. Ideally, the device preserves the input power and simply trades off forces against movement to obtain a desired amplification in the output force...

 in applying torque

Torque

Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....

 to turn objects—usually rotary fastener

Fastener

A fastener is a hardware device that mechanically joins or affixes two or more objects together.Fasteners can also be used to close a container such as a bag, a box, or an envelope; or they may involve keeping together the sides of an opening of flexible material, attaching a lid to a container,...

s, such as nuts

Nut (hardware)

A nut is a type of hardware fastener with a threaded hole. Nuts are almost always used opposite a mating bolt to fasten a stack of parts together. The two partners are kept together by a combination of their threads' friction, a slight stretch of the bolt, and compression of the parts...

 and bolts

Screw

A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the...

—or keep them from turning.

In British English

British English

British English, or English , is the broad term used to distinguish the forms of the English language used in the United Kingdom from forms used elsewhere...

, spanner is the standard term. The most common shapes are called open-ended spanner and ring spanner. The term wrench refers to a type of adjustable spanner.

In American English

American English

American English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....

, wrench is the standard term. The very most common shapes are called open-end wrench and box-end wrench. In American English, spanner refers to a specialized 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.

Higher quality wrenches are typically made from chromium

Chromium

Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...

-vanadium

Vanadium

Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery gray, ductile and malleable transition metal. The formation of an oxide layer stabilizes the metal against oxidation. The element is found only in chemically combined form in nature...

 alloy tool steel

Tool steel

Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools. Their suitability comes from their distinctive hardness, resistance to abrasion, their ability to hold a cutting edge, and/or their resistance to deformation at elevated temperatures...

s and are often drop-forged. They are frequently chrome-plated

Chrome plating

Chrome plating, often referred to simply as chrome, is a technique of electroplating a thin layer of chromium onto a metal object. The chromed layer can be decorative, provide corrosion resistance, ease cleaning procedures, or increase surface hardness.-Process:A component to be chrome plated will...

 to resist corrosion

Corrosion

Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...

 and ease cleaning.

Hinged tools, such as pliers

Pliers

Pliers are a hand tool used to hold objects firmly, for bending, or physical compression. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longer handles on the other...

 or tongs

Tongs

Tongs are used for gripping and lifting tools, of which there are many forms adapted to their specific use. Some are merely large pincers or nippers, but the greatest number fall into three classes:...

, are not generally considered wrenches in American English, but exceptions are the plumber wrench

Plumber wrench

A plumber wrench is a tool to rotate pipes used in plumbing. The wrench is adjusted to different pipe diameters by rotating the key ring . This tool can close with significant force and thus does not need to engage a nut...

 and mole wrench

Locking pliers

Locking pliers, Mole grips or Vise-Grips are pliers that can be locked into position, using an over-center action. One side of the handle includes a bolt that is used to adjust the spacing of the jaws, the other side of the handle often includes a lever to push the two sides of the handles apart...

.

History

Wrenches have existed for many centuries, but saw a great blossoming of development starting in the 19th century

19th century

The 19th century was a period in history marked by the collapse of the Spanish, Portuguese, Chinese, Holy Roman and Mughal empires...

. The first patent for a wrench was granted in 1835 to Solymon Merrick.

Types

	| American name	| British name	| Description	Group
	box-end wrench	ring spanner	A one-piece wrench with an enclosed opening that grips the faces of the bolt or nut. The recess is generally a six-point or twelve-point opening for use with nuts or bolt heads with a hexagonal shape. The twelve-point fits onto the fastening at twice as many angles, an advantage where swing is limited. Eight-point wrenches are also made for square-shaped nuts and bolt heads. Ring spanners are often double-ended and usually with offset handles to improve access to the nut or bolt.	common
	spark plug wrench	box spanner / tube spanner	A tube with six-sided sockets on both ends. It is turned with a short length of rod (tommy bar or T bar) inserted through two holes in the middle of the tube.	common
	combination wrench	combination spanner	A double-ended tool with one end being like an open-end wrench or open-ended spanner, and the other end being like a box-end wrench or ring spanner. Both ends generally fit the same size of bolt.	common
	open-end wrench	open-ended spanner	A one-piece wrench with a U-shaped opening that grips two opposite faces of the bolt or nut. This wrench is often double-ended, with a different-sized opening at each end. The ends are generally oriented at an angle of around 15 degrees to the longitudinal axis of the handle. This allows a greater range of movement in enclosed spaces by flipping the wrench over.	common
	flare-nut wrench tube wrench line wrench	crow's-foot spanner	A wrench that is used for gripping the nuts on the ends of tubes. It is similar to a box-end wrench but, instead of encircling the nut completely, it has a narrow opening just wide enough to allow the wrench to fit over the tube, and thick jaws to increase the contact area with the nut. This allows for maximum contact on plumbing nuts, which are typically softer metals and therefore more prone to damage from open-ended wrenches.	common
	ratcheting box wrench	ratcheting ring spanner	A type of ring spanner, or box wrench, whose end section ratchet Ratchet (device) A ratchet is a device that allows continuous linear or rotary motion in only one direction while preventing motion in the opposite direction. Because most socket wrenches today use ratcheting handles, the term "ratchet" alone is often used to refer to a ratcheting wrench, and the terms "ratchet"... s. Ratcheting can be reversed by flipping over the wrench, or by activating a reversing lever on the wrench. This type of wrench combines compact design of a box wrench, with the utility and quickness of use of a ratchet wrench. A variety of ratcheting mechanisms are used, from simple pawls to more complex captured rollers, with the latter being more compact, smoother, but also more expensive to manufacture.	common
	Saltus wrench	?	Similar in concept to a socket wrench. A Saltus wrench features a socket permanently affixed to a handle. Sockets are not interchangeable as with a socket wrench. The socket often rotates around the handle to allow the user to access a fastener from a variety of angles. Commonly a Saltus wrench is part of a double-ended wrench, with an open-end type head on the opposite side from the socket head.	common
		/ C spanner / hook spanner	A wrench with one or several pins or hooks, designed to drive spanner head screws, threaded collars and retainer rings, shafts, and so on. Note the difference in the American and British senses of the word "spanner".	common
	striking face box wrench slammer wrench slugger wrench hammer wrench	slogging spanner flogging spanner	This is a specialized thick, short, stocky wrench with a block end to the handle specifically designed for use with a hammer, enabling one to impart great force. Used commonly with large fasteners, especially a nut and stud which both have index marks: the nut is screwed hand-tight, then further tightened with the striking wrench a known number of index marks calculated from the elasticity of the bolt or stud, thus giving precise torque (preload). Striking wrenches also provide shock and high force used to release large and/or stuck nuts and bolts; and when space does not allow room for a large wrench.	common
	adjustable wrench adjustable end wrench	adjustable spanner Adjustable spanner An adjustable spanner or adjustable wrench is a spanner with a "jaw" of adjustable width, allowing it to be used with different sizes of fastener head rather than just one faster, as with a conventional fixed spanner... shifting spanner shifter	The most common type of adjustable wrench in use today. The adjustable end wrench differs from the monkey wrench in that the gripping faces of the jaws are displaced to a (typically) 15 degree angle relative to the tool's handle, a design feature that facilitates the wrench's use in close quarters. The modern adjustable end wrench was invented by Johan Petter Johansson Johan Petter Johansson Johan Petter Johansson , sometimes known as JP, was a Swedish inventor and industrialist. He invented a modern adjustable spanner . He obtained over 100 patents in total....  of Bahco Bahco Bahco is an international brand within the hand tool industry, with its products designed and manufactured by SNA Europe. Its roots go back to the industrial revolution of Sweden in the late eighteen hundreds, starting with innovations such as the pipe wrench and the modern adjustable wrench... . Most common brand in the US is Crescent, so there it is often referred to as a "crescent wrench", regardless of manufacturer.	adjustable
	monkey wrench Monkey wrench The monkey wrench is an adjustable wrench, a later American development of eighteenth century English coach wrenches. It was popular in the nineteenth and early twentieth centuries but is now used only for heavier tasks, having been mostly replaced by the lighter and sleeker shifting adjustable or...	gas grips	An old type of adjustable wrench with a straight handle and smooth jaws whose gripping faces are perpendicular to the handle.	historical
	pipe wrench Pipe wrench The pipe wrench is an adjustable wrench used for turning soft iron pipes and fittings with a rounded surface. The design of the adjustable jaw allows it to rock in the frame, such that any forward pressure on the handle tends to pull the jaws tighter together. Teeth angled in the direction of turn...	Stillson wrench or Stillsons	A tool that is similar in design and appearance to a monkey wrench, but with self-tightening properties and hardened, serrated jaws that securely grip soft iron pipe and pipe fittings. Sometimes known by the original patent holder's brand name as a Stillson wrench.	adjustable
	socket wrench Socket wrench A socket wrench is a wrench with interchangeable heads called sockets that attach to a fitting on the wrench, allowing it to turn different sized bolts and other fasteners. The most common form is a hand tool popularly called a ratchet consisting of a handle with a ratcheting mechanism built in,...	socket wrench Socket wrench A socket wrench is a wrench with interchangeable heads called sockets that attach to a fitting on the wrench, allowing it to turn different sized bolts and other fasteners. The most common form is a hand tool popularly called a ratchet consisting of a handle with a ratcheting mechanism built in,...	A hollow cylinder that fits over one end of a nut or bolt head. It may include a handle, if it does not then it is often just referred to as a socket and is usually used with various drive tools to make it a wrench or spanner such as a ratchet handle, a tee bar (sliding tommy bar) bar or a knuckle bar (single axis pivot). It generally has a six-point, eight-point or twelve-point recess, may be shallow or deep, and may have a built-in universal joint Universal joint A universal joint, universal coupling, U joint, Cardan joint, Hardy-Spicer joint, or Hooke's joint is a joint or coupling in a rigid rod that allows the rod to 'bend' in any direction, and is commonly used in shafts that transmit rotary motion... . (The photo shows both ratchet and sockets.)	socket
	breaker bar Breaker bar A breaker bar is a long non-ratcheting bar that is used with socket wrench style sockets. Breaker bars are used to 'break loose' very tight fasteners because their additional length allows the same amount of force to generate significantly more torque than a standard length socket wrench. The use... break-over handle	jointed nut spinner flex head nut spinner	This tool is a long non-ratcheting bar that allows the user to impart considerable torque Torque Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....  to fasteners, especially in cases where corrosion Corrosion Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...  has resulted in a difficult-to-loosen part.	socket
	crowfoot wrench crow's-foot wrench	?	A type of socket designed to fit some of the same drive handles as the regular socket but non-cylindrical in shape. The ends are the same as those found on the open-end, box-end, or the flare-nut wrenches. These sockets use for use where space restrictions preclude the use of a regular socket. Their principal use is with torque wrenches.	socket
	ratchet wrench	ratchet handle	It contains a one-way mechanism which allows the socket to be turned without removing it from the nut or bolt simply by cycling the handle backward and forward. (The photo shows both ratchet and sockets.)	socket
	speed handle	speed handle crank handle speed brace	A crank-shaped handle that drives a socket. The socket-driving analog of the brace used to drive a drill bit Brace (tool) A brace or brace and bit is a hand tool used to drill holes, usually in wood. Pressure is applied to the top and the tool is rotated with a U-shaped grip.... . Used instead of a ratchet in a few contexts when it can save substantial time and effort—that is, when there is a lot of turning to be done (many fasteners), ample room to swing the handle, ample access to the fastener heads, etc. Used occasionally in automotive repair or job shop work.	socket
	torque wrench Torque wrench A torque wrench is a tool used to precisely apply a specific torque to a fastener such as a nut or bolt. It is usually in the form of a socket wrench with special internal mechanisms. It was invented by Conrad Bahr in 1918 while working for the New York City Water Department...	torque wrench Torque wrench A torque wrench is a tool used to precisely apply a specific torque to a fastener such as a nut or bolt. It is usually in the form of a socket wrench with special internal mechanisms. It was invented by Conrad Bahr in 1918 while working for the New York City Water Department...	A socket wrench drive tool that is employed to impart a precise amount of torque to a fastener, essential in many cases during the assembly of precision mechanisms.	socket
	Allen wrench Allen key hex key	Allen key	A wrench used to turn screw or bolt heads designed with a hexagonal socket (recess) to receive the wrench. The wrenches come in two common forms: L-shaped and T-handles. The L-shaped wrenches are formed from hexagonal wire stock, while the T-handles are the same hex wire stock with a metal or plastic handle attached to the end. There are also indexable-driver-bits that can be used in indexable screwdrivers.	keys
	Bristol wrench Bristol spline wrench	?	Another wrench designed for internal socket-head screws and bolts. The cross-section resembles a square-toothed gear. Not a common design, it is chiefly used on small set screw Set screw A set screw is a type of screw generally used to secure an object within or against another object. The most common examples are securing a pulley or gear to a shaft. Set screws are most often headless , meaning that the screw is fully threaded and has no head projecting past the major diameter of... s.	keys
	Torx wrench	Torx key	An internal socket-head screw design. The cross-section resembles a star. Commonly used in automobiles, automated equipment, and computer components as it is resistant to wrench cam-out and so suitable for use in the types of powered tools used in production-line assembly.	keys
	power wrench Power wrench A power wrench is type of wrench that is powered by other means than human force. A typical power source is compressed air. There are two main types of power wrenches: impact wrenches and air ratchet wrenches or pneumatic ratchet wrenches....	?	A broad type of wrenches that use electricity or compressed air to power the wrench.	power
	impact wrench Impact wrench An impact wrench is a socket wrench power tool designed to deliver high torque output with minimal exertion by the user, by storing energy in a rotating mass, then delivering it suddenly to the output shaft.Compressed air is the most common power source, although electric or hydraulic... /impact driver	Rattle gun/impact driver	A compressed air (pneumatic) powered wrench commonly used in car garages and workshops to tighten and remove wheel nuts. Includes a mechanism to provide repeating pulsed force, good for loosening stuck fasteners and also for overcoming stiction Stiction Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact. The term is a portmanteau of the term "static friction", perhaps also influenced by the verb "stick"....  when tightening, to assure consistent tightness.	power
	alligator wrench	?	A formerly common type of wrench that was popular with mechanics, factory workers, and farmers for maintenance, repair and operations Maintenance, Repair and Operations Maintenance, repair, and operations or maintenance, repair, and overhaul involves fixing any sort of mechanical or electrical device should it become out of order or broken...  tasks in the days when fasteners often had square rather than hex heads. The wrench's shape suggests the open mouth of an alligator.	historical
	cone wrench Cone wrench A cone wrench is a tool used in bicycle maintenance to access flats on axles where very little of the axle is exposed.It is similar to an open-ended wrench but much thinner: typically about 2 mm thick, compared to approximately 7 mm for a standard open-ended wrench....	cone spanner	A thin open-end wrench used to fit narrow wrench flats of adjustable bearing bicycle hubs Bicycle wheel A bicycle wheel is a wheel, most commonly a wire wheel, designed for bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels.... . Called a "cone" wrench because it fits wrench flats of the cone section of a "cup and cone" hub, this tool is also used with some other adjustable hub bearings. The wrench is very thin so has little strength; to compensate, cone wrenches typically have a large head. Most bicycle front hubs use a 13 mm; most rears use 15 mm.	specialty
	die wrench die-stocks	?	A double-handled wrench for turning the dies Taps and dies Taps and dies are cutting tools used to create screw threads, which is called threading. A tap is used to cut the female portion of the mating pair . A die is used to cut the male portion of the mating pair . The process of cutting threads using a tap is called tapping, whereas the process using a...  used in threading operations (cutting the male threads such as on a bolt).	specialty
	drum key  lug wrench drum wrench	Drum key	A small, square-head socket wrench used on drum tuning lugs and fasteners. This key is often interchangeable with radiator bleed keys.	specialty
	drum wrench Drum wrench The drum wrench is a tool which is commonly used to open large 55-gallon drums.When unopened, a large drum's contents may be under enormous pressure. If a drum is opened without the proper tools and precautions, the pressure may escape suddenly and violently, causing injury. A drum wrench reduces...   bung wrench	?	A tool commonly used to open bungs on large 55-gallon drums.	specialty
	fire hydrant wrench (hose connection)	?	The hose connection has a threaded collar with a protruding pin. From the handle of the wrench an arc has at its end a loop to engage the pin.	specialty
	fire hydrant wrench (valve operator)	?	This is a pentagonal (five-sided) box wrench. Avoiding a hex shape for the lug makes the valve tamper-resistant Tamper resistance Tamper resistance is resistance to tampering by either the normal users of a product, package, or system or others with physical access to it. There are many reasons for employing tamper resistance.... : with the opposite faces nonparallel, unauthorized opening of the hydrant is less likely, because the would-be opener lacks a suitable tool. See also "curb key" on this page.	specialty
	curb key	?	This is a wrench for opening and closing valves on municipal water pipes (often at the curb, hence the name). It can be similar to a fire hydrant key, because both may have the pentagon drive for tamper resistance.	specialty
	golf shoe spike wrench	?	A T-handle wrench with two pins and clearance for the spike—allows removal and insertion of spikes in shoes.	specialty
	head nut wrench	?	A flat wrench with a circular hole and two inward protruding pins to engage slots in the nut. This type of nut is used on bicycles to secure the front fork pivot bearing to the headpiece of the frame.	specialty
	4-way lug wrench	wheel brace	A socket wrench used to turn lug nuts on automobile Automobile An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...  wheels Wheel A wheel is a device that allows heavy objects to be moved easily through rotating on an axle through its center, facilitating movement or transportation while supporting a load, or performing labor in machines. Common examples found in transport applications. A wheel, together with an axle,... .	specialty
	oil-filter wrench Oil-filter wrench An oil-filter wrench is a tool for removing spin-on type oil filters. These filters are smooth, cylindrical canisters with knurling on the bottom that are difficult to grip, especially when they are oily.One common type of wrench is shown on the right...	Oil filter wrench or chain wrench	A type of wrench for removing cylindrical oil filters. It may be either a strap-type wrench or a socket.	specialty
	plumber wrench Plumber wrench A plumber wrench is a tool to rotate pipes used in plumbing. The wrench is adjusted to different pipe diameters by rotating the key ring . This tool can close with significant force and thus does not need to engage a nut...	Multigrips or multigrip pliers	A tool to screw (rotate with force) various pipes during plumbing Plumbing Plumbing is the system of pipes and drains installed in a building for the distribution of potable drinking water and the removal of waterborne wastes, and the skilled trade of working with pipes, tubing and plumbing fixtures in such systems. A plumber is someone who installs or repairs piping... .	specialty
	?	rigger-jigger	A spanner used in attaching riggers to rowing Rowing (sport) Rowing is a sport in which athletes race against each other on rivers, on lakes or on the ocean, depending upon the type of race and the discipline. The boats are propelled by the reaction forces on the oar blades as they are pushed against the water...  boats with offset to allow users fingers to keep grip when flush with boat. 10 mm at one end, 13 mm at the other.	specialty
	sink wrench Sink wrench A sink wrench, also known as a basin wrench, is a plumbing tool used to tighten connections in deeply recessed places. That are very hard to get at normally.... basin wrench	basin wrench	A self-tightening wrench mounted at the end of a torque tube with a transverse handle at the opposite end. Used to tighten tubing connections to washstand valves in ceramic sinks—the nuts are often located deep in recesses. The self-tightening head may be flipped over to loosen connections.	specialty
	spoke wrench Spoke wrench A spoke wrench or spoke key is a small wrench or tool used to adjust the tension in the spokes of a bicycle wheel, sulky wheel, wheelchair wheel, or similar...	nipple wrench or spoke key	A wrench with a clearance slot for a wire wheel spoke such as a bicycle wheel and a drive head for the adjustment nipple nut. The handle is offset to make the wrench more convenient to grip, and the handle is short to fit between spokes, allowing the wrench to turn 360 degrees without being removed.	specialty
		podging spanner podger	A steel erecting tool which consists of a normal wrench at one end and a spike at the other, used for lining up bolt holes (typically when mating two pipe flanges).	specialty
	chain whip		A self-tightening wrench that engages the teeth of a chain drive sprocket, and used typically to remove bicycle cogsets. Similar to a strap wrench Strap wrench A strap wrench is any of various types of wrench that grip an object via a strap or chain being pulled in tension around it until it firmly grips. High static friction keeps it from slipping.... , but uses positive engagement rather than friction, and so needs to grab only one end of the chain.	specialty
	strap wrench Strap wrench A strap wrench is any of various types of wrench that grip an object via a strap or chain being pulled in tension around it until it firmly grips. High static friction keeps it from slipping.... chain wrench	strap wrench Strap wrench A strap wrench is any of various types of wrench that grip an object via a strap or chain being pulled in tension around it until it firmly grips. High static friction keeps it from slipping.... chain wrench	A self-tightening wrench with either a chain or strap of metal, leather, or rubber attached to a handle, used to grip and turn smooth cylindrical objects (such as automotive oil filters). It relies entirely on friction between the strap or chain and the object to be manipulated. Similar to a pipe wrench Pipe wrench The pipe wrench is an adjustable wrench used for turning soft iron pipes and fittings with a rounded surface. The design of the adjustable jaw allows it to rock in the frame, such that any forward pressure on the handle tends to pull the jaws tighter together. Teeth angled in the direction of turn... , but uses a chain similar to a drive chain or strap, instead of an adjustable jaw. The links of the chain have extended pegs which fit into grooves in the front of the handle, with one end of the chain attached permanently to the handle. This is used in situations where pipe wrenches cannot maintain a proper grip on an object such as a wet or oily pipe. Larger versions of chain wrenches are sometimes known as "bull tongs" and are used with large diameter pipe such as is used deep wells.	specialty
	tap wrench Tap wrench A tap wrench is a hand tool used to turn taps or other small tools, such as hand reamers and screw extractors.-Types:There are two main types of tap wrenches: double-end adjustable wrenches and T-handle wrenches. Double-end adjustable wrenches, also known as bar wrenches, have one threaded handle... tap handle T-handle	tap wrench Tap wrench A tap wrench is a hand tool used to turn taps or other small tools, such as hand reamers and screw extractors.-Types:There are two main types of tap wrenches: double-end adjustable wrenches and T-handle wrenches. Double-end adjustable wrenches, also known as bar wrenches, have one threaded handle...	A double-handled wrench for turning the square drive on taps Taps and dies Taps and dies are cutting tools used to create screw threads, which is called threading. A tap is used to cut the female portion of the mating pair . A die is used to cut the male portion of the mating pair . The process of cutting threads using a tap is called tapping, whereas the process using a...  used in threading operations (cutting the female threads such as within a nut) or a precision reamer Reamer A reamer is a metalworking tool used to create an accurate sized hole. The process is called reaming. They may be used as a hand tool or in a machine tool, such as a milling machine or drill press.-Construction:... .	specialty
	tappet wrench	?	A spanner of small to moderate size constructed similarly to an open ended wrench, but with a thinner cross section. Its purpose is to apply torque to the fasteners found on the valve trains of older engines, especially automobile engines, where the valve train required adjustment of the tappets (also known as lifters). Tappets, push rods, rocker arms and similar adjustable pieces are often equipped with locknuts which are thinner than standard nuts, due to space limitations. Frequently, the hex section of the adjustment is contiguous to the lock nut, thus requiring a thinner "tappet wrench" to be used.	specialty
	tuning wrench Tuning wrench A tuning wrench is a specialized socket wrench used to tune string instruments such as the piano, harp, and hammer dulcimer, that have strings wrapped around tuning pins with square heads...	tuning "T" hammer piano tuning lever	A socket wrench used to tune some stringed musical instruments. Similar, and in some cases identical to drum tuning keys, but often provide greater torque due to the higher tension of strings.	specialty
	wing nut wrench		A tool specifically for use with wing nuts, allowing the application of greater torque than is possible by hand. It is generally advised not to use such spanners for tightening the wing nut, but rather only for loosening. It is a "hand saver" more than anything else.	specialty
	graduated wrench	?	An adjustable wrench with a small number (usually 2–4) of discrete sizes. This is sometimes used as an inexpensive substitute for a monkey wrench.

Other types of keys

These types of keys are not emically

Emic and etic

Emic and etic are terms used by anthropologists and by others in the social and behavioral sciences to refer to two kinds of data concerning human behavior...

 classified as wrenches by English speakers, but they are etically similar in function to wrenches.

	| American name	| British name	| Description	Group
		chuck key	A key used to tighten or loosen a chuck Chuck (engineering) A chuck is a specialized type of clamp used to hold an object, usually an object with radial symmetry, especially a cylindrical object. It is most commonly used to hold a rotating tool or a rotating workpiece... .	household/industrial
	church key, bottle opener	church key, bottle opener	A key used to remove bottle caps or to pierce can lids.	household
		?	A key used to open the lids of paint cans. Its upturned edge helps to apply a levering motion to the crimped lip of the can lid.	household
		sillcock key, loose key, tap key	A key used to open or close sillcock valves. Many are designed the same way as a spider-type lug wrench, with four common sizes (one on each end) built into one portable tool.	household
		window crank	A socket-like key slipped over the splined shaft that operates the opening and closing of some types of window.	household
		sardine tin key	A key used in opening the lids of canned fish or canned meat.	household

External links

• Spanner Jaw Sizes Additional background information and spanner jaw size table.
• Conversion chart Whitworth/BSF/AF and metric spanner and thread sizes