Kilogram-force per square centimetre
Unit of pressure
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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.
| 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 × .0254 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
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.