Pressure and Stress

Top  Previous  Next

The following units are included in this section:

 

ID

Unit

Definition

Wikipedia page and other notes

1

pascal (Pa, N/m2)

-

https://en.wikipedia.org/wiki/Pascal_(unit)

The same as newton per sq. metre

2

newton per sq. metre (N/m2, Pa)

1 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

The same as pascal

3

newton per sq. centimetre (N/cm2)

104 Pa

 

4

newton per sq. millimetre (N/mm2)

106 Pa

 

5

hectopascal (hPa)

102 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

6

kilopascal (kPa, kN/m2)

103 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

7

kilonewton per sq. metre (kN/m2, kPa)

103 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

8

kilonewton per sq. centimetre (kN/cm2)

107 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

9

kilonewton per sq. millimetre (kN/mm2)

109 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

10

megapascal (MPa, MN/m2)

106 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

11

meganewton per sq. metre  (MN/m2, MPa)

106 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

12

gigapascal (GPa, GN/m2)

109 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

13

giganewton per sq. metre (GN/m2, GPa)

109 Pa

https://en.wikipedia.org/wiki/Pascal_(unit)

Page refers to pascal

14

bar

105 Pa

https://en.wikipedia.org/wiki/Bar_(unit)

15

kilobar (kbar)

108 Pa

https://en.wikipedia.org/wiki/Bar_(unit)

Page refers to bar

16

megabar (Mbar)

1011 Pa

https://en.wikipedia.org/wiki/Bar_(unit)

Page refers to bar

17

gigabar (Gbar)

1014 Pa

https://en.wikipedia.org/wiki/Bar_(unit)

Page refers to bar

18

millibar (mbar)

102 Pa

https://en.wikipedia.org/wiki/Bar_(unit)

Page refers to bar

19

microbar (μbar)

10-1 Pa

https://en.wikipedia.org/wiki/Bar_(unit)

Page refers to bar

20

pound-force per sq. inch (psi, lbf/in2)

(444,822,161.52605/64,516) Pa

https://en.wikipedia.org/wiki/Pounds_per_square_inch

21

pound-force per sq. foot (psf)

(1/144) psi

 

22

kilopound-force per sq. inch (ksi)

103 psi

https://en.wikipedia.org/wiki/Pounds_per_square_inch#Multiples

23

kilopound-force per sq. foot (ksf)

(103/144) psi

 

24

megapound-force per sq. inch (Mpsi)

106 psi

https://en.wikipedia.org/wiki/Pounds_per_square_inch#Multiples

25

megapound-force per sq. foot (Mpsf)

(106/144) psi

 

26

millimetre of mercury [conv.] (mmHg)

133.322387415 Pa

https://en.wikipedia.org/wiki/Millimeter_of_mercury

Conventionally, the density 13,595.1 kg/m3 is used for mercury for this definition, which is the approximate density of mercury at 0 °C (32 °F), and 9.80665 m/s2 is standard gravity:

13595.1*9.80665 = 133,322.387415 for 1 metre of mercury

 

27

centimetre of mercury [conv.] (cmHg)

1333.22387415 Pa

https://en.wikipedia.org/wiki/Millimeter_of_mercury

Page refers to “Millimeter of mercury”

28

inch of mercury [conv.] (inHg)

3386.388640341 Pa

https://en.wikipedia.org/wiki/Inch_of_mercury

29

foot of mercury [conv.] (ftHg)

40,636.663684092 Pa

https://en.wikipedia.org/wiki/Inch_of_mercury
Page refers to inch of mercury

30

millimetre of water [conv.] (mmAq)

9.80665 Pa

https://en.wikipedia.org/wiki/Millimeters,_water_gauge

Conventionally, the density 1,000 kg/m3 is used for water for this definition, which is the approximate density of water at 4 °C (39.2 °F), and 9.80665 m/s2 is standard gravity:

1000*9.80665 = 9806.65 for 1 metre of water

Note: The maximum density of water is 999.972 kg/m3 at a temperature of 3.98 °C (39.164 °F) but conventionally we use a value of 1000 kg/m3 for water for the definition of this unit

31

centimetre of water [conv.] (cmAq)

98.0665 Pa

https://en.wikipedia.org/wiki/Centimetre_of_water

32

inch of water [conv.] (inAq)

249.08891 Pa

https://en.wikipedia.org/wiki/Inch_of_water

33

foot of water [conv.] (ftAq)

2989.06692 Pa

https://en.wikipedia.org/wiki/Inch_of_water

Page refers to inch of water

34

atmosphere [standard] (atm)

101,325 Pa

https://en.wikipedia.org/wiki/Atmosphere_(unit)

35

kilogram-f per sq. metre (kgf/m2)

9.80665 Pa

 

36

kilogram-f per sq. cm (kgf/cm2, at)

98,066.5 Pa

https://en.wikipedia.org/wiki/Kilogram-force_per_square_centimetre

The same as “Technical atmosphere”

37

atmosphere [technical] (at, kgf/cm2)

98,066.5 Pa

https://en.wikipedia.org/wiki/Technical_atmosphere

The same as “kilogram-f per sq. cm”

38

torr (Torr)

(1/760) atm

https://en.wikipedia.org/wiki/Torr

39

dyne per sq. metre (dyn/m2)

10-5 Pa

 

40

dyne per sq. centimetre (dyn/cm2, barye)

10-1 Pa

https://en.wikipedia.org/wiki/Barye

The same as “barye”

41

barye (Ba, dyn/cm2)

10-1 Pa

https://en.wikipedia.org/wiki/Barye

The same as “dyne per sq. centimetre”

42

pièze (pz)

103 Pa

https://en.wikipedia.org/wiki/Pi%C3%A8ze

 

All the above definitions of the various units are EXACT.

Note that for the units based on mercury (millimetre of mercury [conv.] (mmHg), centimetre of mercury [conv.] (cmHg), inch of mercury [conv.] (inHg), foot of mercury [conv.] (ftHg)) and the units based on water (millimetre of water [conv.] (mmAq), centimetre of water [conv.] (cmAq), inch of water [conv.] (inAq), foot of water [conv.] (ftAq)), other similar definitions can be found in the literature, referring to different base temperatures, as the density of the material depends on its temperature. In the above we have used the conventional values that can be found in the literature.

 

Note: In the above, a period (.) is used to indicate the decimal place and a comma (,) is used to separate groups of thousands.

 

Type of conversion relationship: DIRECTLY PROPORTIONAL (y=ax)

Example conversion diagram (see two units in bold above):

Pressure