# Pounds per square inch

psilb f /in 2 psiglbf/in²ksipounds-force per square inchpsiap.s.i.pound per square inchlbf/in 2
The pound per square inch or, more accurately, pound-force per square inch (symbol: lbf/in 2 ; abbreviation: psi) is a unit of pressure or of stress based on avoirdupois units.wikipedia
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### Atmospheric pressure

barometric pressureair pressurepressure
The standard atmosphere (symbol: atm) is a unit of pressure defined as 101325 Pa, equivalent to 760mm Hg, 29.9212inchesHg, or 14.696psi.

### Pound (force)

lbflb f pound-force
It is the pressure resulting from a force of one pound-force applied to an area of one square inch.

### Inch of water

inches of waterinH 2 Oin H 2 O
This is in contrast to inches of mercury or pounds per square inch (psi, lbf/in) for larger pressures.

### Pressure

water pressurenegative pressurefluid pressure
The pound per square inch or, more accurately, pound-force per square inch (symbol: lbf/in 2 ; abbreviation: psi) is a unit of pressure or of stress based on avoirdupois units.
Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m 2 ); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and US customary systems.

### Pressure measurement

manometerpressure gaugegauge pressure
A vacuum gauge is a pressure gauge used to measure pressures lower than the ambient atmospheric pressure, which is set as the zero point, in negative values (e.g.: −15 psig or −760 mmHg equals total vacuum).

### Ultimate tensile strength

tensile strengthtensileultimate strength
They are mostly used in materials science, where the tensile strength of a material is measured as a large number of psi.
A United States customary unit is pounds per square inch (lb/in² or psi), or kilo-pounds per square inch (ksi, or sometimes kpsi), which is equal to 1000 psi; kilo-pounds per square inch are commonly used in one country (US), when measuring tensile strengths.

### Millimetre of mercury

mmHgmm Hgmillimetres of mercury

### Pascal (unit)

hPaMPakPa
The pascal (Pa) or kilopascal (kPa) as a unit of pressure measurement is widely used throughout the world and has largely replaced the pounds per square inch (psi) unit, except in some countries that still use the imperial measurement system or the US customary system, including the United States.

### Conversion of units

conversion factorunit conversionConversions

### United States customary units

USUS customary unitsU.S. customary units

### Avoirdupois system

avoirdupoislbavoirdupois ounce
The pound per square inch or, more accurately, pound-force per square inch (symbol: lbf/in 2 ; abbreviation: psi) is a unit of pressure or of stress based on avoirdupois units.

### Square inch

in 2 in²inches square
It is the pressure resulting from a force of one pound-force applied to an area of one square inch.

### International System of Units

SISI unitsSI unit
In SI units, 1 psi is approximately equal to 6895 N/m 2.

### Newton (unit)

kNnewtonN
In SI units, 1 psi is approximately equal to 6895 N/m 2.

### Square metre

m 2 square meter
In SI units, 1 psi is approximately equal to 6895 N/m 2.

### Vacuum

free spaceevacuatedhigh vacuum
Pounds per square inch absolute (psia) is used to make it clear that the pressure is relative to a vacuum rather than the ambient atmospheric pressure.

### Sea level

mean sea levelMSLAMSL
Since atmospheric pressure at sea level is around 14.7 psi, this will be added to any pressure reading made in air at sea level.

### Materials science

material sciencematerials engineeringmaterials scientist
They are mostly used in materials science, where the tensile strength of a material is measured as a large number of psi.

### Mechanics

mechanicaltheoretical mechanicsmechanician
It is used in mechanics for the elastic modulus of materials, especially for metals.

### Elastic modulus

modulus of elasticityelastic modulimodulus
It is used in mechanics for the elastic modulus of materials, especially for metals.

### Blood pressure

systolic blood pressurediastolic blood pressurearterial blood pressure

### Natural gas

gasgas-firednatural-gas

### Turbocharger

turbochargedturbot

### Football (ball)

footballballfootballs

### Railway air brake

Airair brakeair brakes