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).

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, 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

	Pascal	Bar	Technical atmosphere	Standard atmosphere	Torr	Pound per square inch
	(Pa)	(bar)	(at)	(atm)	(Torr)	(psi)
1 Pa	—
1 bar		—	=	=	=	=
1 at			—
1 atm	≡	≡		—	760
1 Torr				Template:Sfrac ≈	—
1 psi						—

1 at	= 98.0665 kPa
	≈ standard atmospheres

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.