Kilogram-force Per Square Centimetre - Wikipedia

Unit of pressure

Kilogram-force per square centimetre
Soviet-made pressure gauges using kgf/cm2
General information
Unit of	Pressure
Symbol	kgf/cm2, at
Conversions
1 kgf/cm2 in ...	... is equal to ...
SI units	98.06650 kPa
FPS units	14.22334 psi

A kilogram-force per square centimetre (kgf/cm2), often just kilogram per square centimetre (kg/cm2), or kilopond per square centimetre (kp/cm2) is a deprecated unit of pressure using metric units. It is not a part of the International System of Units (SI), the modern metric system. 1 kgf/cm2 equals 98.0665 kPa (kilopascals) or 0.980665 bar—2% less than a bar. It is also known as a technical atmosphere (symbol: at).[1][2]

Use of the kilogram-force per square centimetre continues primarily due to older pressure measurement devices still in use.

This use of the unit of pressure provides an intuitive understanding for how a body's mass, in contexts with roughly standard gravity, can apply force to a scale's surface area, i.e. kilogram-force per square (centi-)metre.

In SI units, the unit is converted to the SI derived unit pascal (Pa), which is defined as one newton per square metre (N/m2). A newton is equal to 1 kg⋅m/s2, and a kilogram-force is 9.80665 N,[3] meaning that 1 kgf/cm2 equals 98.0665 kilopascals (kPa).

In some older publications, kilogram-force per square centimetre is abbreviated ksc instead of kgf/cm2.

Pressure units

v t e	Pascals	Bars	Standard atmospheres	Pounds per square inch	Millimetres of mercury	Inches of mercury	Technical atmospheres	Torrs
1 Pa	≡ 1 N⁄m2	= 1×10−5 bar	≈ 9.86923×10−6 atm	≈ 1.45038×10−4 psi	≈ 7.50062×10−3 mmHg	≈ 2.95300×10−4 inHg	≈ 1.01972×10−5 kgf/cm2	≈ 7.50062×10−3 Torr
1 bar	= 100000 Pa	≡ 100 000 N⁄m2	≈ 0.98692 atm	≈ 14.5038 psi	≈ 750.062 mmHg	≈ 29.5300 inHg	≈ 1.01972 kgf/cm2	≈ 750.062 Torr
1 atm	= 101325 Pa	= 1.01325 bar	≡ 101 325 N⁄m2	≈ 14.6959 psi	≈ 760.000 mmHg	≈ 29.9213 inHg	≈ 1.03323 kgf/cm2	= 760 Torr
1 psi	≈ 6894.76 Pa	≈ 0.06895 bar	≈ 0.06805 atm	≡ 1 lb⁄in2	≈ 51.7149 mmHg	≈ 2.03602 inHg	≈ 0.07031 kgf/cm2	≈ 51.7149 Torr
1 mmHg	≈ 133.322 Pa	≈ 1.33322×10−3 bar	≈ 1.31579×10−3 atm	≈ 0.01934 psi	≡ gn × .001 m × 13595.1 kg⁄m3	≈ 0.03937 inHg	≈ 1.35951×10−3 kgf/cm2	≈ 1.00000 Torr
1 inHg	≈ 3386.39 Pa	≈ 0.03386 bar	≈ 0.03342 atm	≈ 0.49115 psi	= 25.4 mmHg	≡ gn × .254 m × 13595.1 kg⁄m3	≈ 0.0345316 kgf/cm2	≈ 25.4000 Torr
1 kgf⁄cm2	≈ 98066.5 Pa	≈ 0.98066 bar	≈ 0.96784 atm	≈ 14.2233 psi	≈ 735.559 mmHg	≈ 28.9590 inHg	≡ 1 kgf⁄cm2	≈ 735.559 Torr
1 Torr	≈ 133.322 Pa	≈ 1.33322×10−3 bar	≈ 1.31579×10−3 atm	≈ 0.01934 psi	≈ 1.00000 mmHg	≈ 0.03937 inHg	≈ 1.35951×10−3 kgf/cm2	≡ ⁠101 325/760⁠ = ⁠20 265/172⁠ N⁄m2

1 at	= 98.0665 kPa
	≈ 0.96784 standard atmospheres

Pressure gauge from unknown source produced by ISGUS GmbH.Pressure gauge from unknown source. Note the visual square instead of 2. (Olja means "oil" in Swedish)

Ambiguity of at

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The symbol "at" clashes with that of the katal (symbol: "kat"), the SI unit of catalytic activity; a kilotechnical atmosphere would have the symbol "kat", indistinguishable from the symbol for the katal. It also clashes with that of the non-SI unit, the attotonne, but that unit would more likely be rendered as the equivalent SI unit, the picogram.

References

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1. ^ Dorf, Richard C. (2003-11-24). CRC Handbook of Engineering Tables. CRC Press. ISBN 9780203009222.
2. ^ Suplee, Curt (2009-07-02). "Special Publication 811". NIST. Retrieved 2019-05-17.
3. ^ The NIST Guide for the use of the International System of Units, National Institute of Standards and Technology, 18 Oct 2011