Gauge ( or ) may refer to:

Measurement

* Gauge (instrument), any of a variety of measuring instruments *

Gauge (firearms) The gauge (or commonly bore in British English) of a firearm is a unit of measurement used to express the inner diameter (bore diameter) of the barrel. Gauge is determined from the weight of a solid sphere of lead that will fit the bore of the ...

Wire gauge Wire gauge is a measurement of wire diameter. This determines the amount of electric current the wire can safely carry, as well as its electrical resistance and weight. Types of wire gauge Wire gauges may be broadly divided into two groups, t ...

, a measure of the size of a wire ** American wire gauge, a common measure of nonferrous wire diameter, especially electrical **

Birmingham gauge The Birmingham gauge is a wire gauge system, and is also used to specify thickness or diameter of hypodermic needles and tube products. Terminology Birmingham gauge is also known as the Stubs Iron Wire Gauge or Birmingham Wire Gauge. It is not t ...

, a measure of ferrous wire and hypodermic needle diameter **

Jewelry wire gauge Jewelry wire is wire, usually copper, brass, nickel, aluminium, silver, or gold, used in jewelry making. Wire is defined today as a single, usually cylindrical, elongated strand of drawn metal. However, when wire was first invented over 2,000 ye ...

, the size of wire used in jewelry making *

Sheet metal gauge Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes. Thicknesses can vary significantly; ex ...

, thickness of metal in sheet form *

Film gauge Film gauge is a physical property of photographic or motion picture film stock which defines its width. Traditionally, the major movie film gauges are 8 mm, 16 mm, 35 mm, and 65/70 mm (in this case 65 mm for the negative and 70 mm f ...

, a physical property of film stock which defines its size * The size of objects used in

stretching (body piercing) Stretching, in the context of body piercing, is the deliberate expansion of a healed piercing for the purpose of wearing certain types of jewelry. Ear piercings are the most commonly stretched piercings, with nasal septum piercings, tongue pierci ...

, especially earrings *

Gauge block Gauge blocks (also known as gage blocks, Johansson gauges, slip gauges, or Jo blocks) are a system for producing precision lengths. The individual gauge block is a metal or ceramic block that has been precision ground and lapped to a specific ...

, a metal or ceramic block of precisely known dimension, used in measuring *

Sight glass Visual perception is the ability to interpret the surrounding environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the visible spectrum reflec ...

, also known as a water gauge, for measuring liquid level heights in storage tanks and pressure vessels * Boost gauge, a gauge used in conjunction with turbo-super-chargers * Pressure gauge or vacuum gauge, see

pressure measurement Pressure measurement is the measurement of an applied force by a fluid (liquid or gas) on a surface. Pressure is typically measured in units of force per unit of surface area. Many techniques have been developed for the measurement of pressu ...

Gauge pressure Pressure measurement is the measurement of an applied force by a fluid ( liquid or gas) on a surface. Pressure is typically measured in units of force per unit of surface area. Many techniques have been developed for the measurement of pre ...

, pressure above ambient pressure * Stream gauge, for measuring height and discharge of a river or stream *

Air core gauge An air core gauge is a specific type of rotary actuator in an analog display gauge that allows an indicator to rotate a full 360 degrees. It is used in gauges and displays, most commonly automotive instrument clusters. A typical automotive app ...

, a type of rotary actuator often used in automotive instruments * Gauger, one who gauges or measures, typically dutiable commodities, such as wine, landed from ships at docks

Sizes

Railway practice

Track gauge In rail transport, track gauge (in American English, alternatively track gage) is the distance between the two rails of a railway track. All vehicles on a rail network must have wheelsets that are compatible with the track gauge. Since many ...

, the distance between the two rails forming a railway track * Loading gauge, the maximum width and height of vehicles (engines, loaded wagons, etc.). *

Structure gauge A structure gauge, also called the minimum clearance outline, is a diagram or physical structure that sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. It specifies the height and width of pl ...

, the minimum size of bridges, tunnels, platforms, etc. *

Axle load An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearin ...

, the weight that an axle exerts on track *

Variable gauge A variable gauge system allows railway vehicles in a train to travel across a break of gauge between two railway networks with different track gauges. For through operation, a train must be equipped with special bogies holding variable gauge w ...

, system to allow railway vehicles to travel across a break of gauge

Medicine

, for metal wire and tube products * French gauge, mainly for catheters

Mathematics and physics

* Gauge theory * Gauge integral *

Gauge fixing In the physics of gauge theories, gauge fixing (also called choosing a gauge) denotes a mathematical procedure for coping with redundant degrees of freedom in field variables. By definition, a gauge theory represents each physically distinct c ...

* Gauge boson * Gauge ( Minkowski functional)

Other uses

* Gauge (knitting), the number of stitches in a given length * Gauge (actress), American pornographic actress * Gauge (band), post-hardcore band from Chicago, Illinois, USA * Gauge, Inc., a manufacturer of microphones and audio accessories *

Change of gauge (aviation) In air transport, a change of gauge for a passenger or cargo flight is a change of aircraft that retains the same flight number.Gauge (software), cross-platform test automation tool