Kilogram-force per square centimetre

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]

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

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	Pascal	Bar	Technical atmosphere	Standard atmosphere	Torr	Pound per square inch
	(Pa)	(bar)	(at)	(atm)	(Torr)	(psi)
1 Pa	—	10−5 bar	1.0197×10−5 at	9.8692×10−6 atm	7.5006×10−3 Torr	0.000145037737730 lbf/in2
1 bar	105	—	= 1.0197	= 0.98692	= 750.06	= 14.503773773022
1 at	98066.5	0.980665	—	0.9678411053541	735.5592401	14.2233433071203
1 atm	≡ 101325	≡ 1.01325	1.0332	—	≡ 760	14.6959487755142
1 Torr	133.322368421	0.001333224	0.00135951	⁠1/760⁠ ≈ 0.001315789	—	0.019336775
1 psi	6894.757293168	0.068947573	0.070306958	0.068045964	51.714932572	—

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

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.