Kilogram-force per square centimetre
# Kilogram-force per square centimetre

A kilogram-force per centimetre square $(kgf/cm^2),$ often just kilogram per square centimetre $(kg/cm^2),$ or kilopond per centimetre square $(kp/cm^2)$ 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 $kgf/cm^2$ equals 98.0665 kPa (kilopascals). It is also known as a technical atmosphere (symbol: at).

The kilogram-force per square centimetre remains active as a measurement of force 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 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 $(N/m^2).$ A newton is equal to 1 $kg⋅m/s^2,$ and a kilogram-force is 9.80665 N, meaning that 1 $kgf/cm^2$ equals 98.0665 kilopascals (kPa).

In some older publications, kilogram-force per square centimetre is abbreviated ksc instead of $kg/cm^2.$

Pressure units :

| vte | Pascal | Bar | Technical atmosphere | Standard atmosphere | Torr | Pound per square inch |
| - | - | - | - | - | - | - |
| vte | (Pa) | (bar) | (at) | (atm) | (Torr) | $(lbf/in^2)$ |
| 1 Pa | — | 1 Pa = $10^{−5}$ bar | 1 Pa = $1.0197×10^{−5}$ at | 1 Pa = $9.8692×10^{−6}$ atm | 1 Pa = $7.5006×10^{−3}$ Torr | 1 Pa = 0.000145037737730 $lbf/in^2$ |
| 1 bar | $10^5$ | — | = 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 $lbf/in^2$ | 6894.757293168 | 0.068947573 | 0.070306958 | 0.068045964 | 51.714932572 | — |

    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.

