Kilopounds Per Square Inch to Standard Atmospheres (ksi to atm)
1 kilopound per square inch equals 68.04596391 standard atmospheres (rounded).
How to convert kilopounds per square inch to standard atmospheres
To convert kilopounds per square inch to standard atmospheres, multiply the number of kilopounds per square inch by 68.04596391. The factor is rounded to 10 significant digits. To go the other way, multiply standard atmospheres by 0.01469594878 (rounded).
standard atmospheres = kilopounds per square inch × 68.04596391
Example: 10 kilopounds per square inch = 680.4596391 standard atmospheres.
About these units
Kilopound Per Square Inch (ksi)
1,000 psi (about 6.895 MPa). Used for the strength of materials such as steel in US engineering.
Thousands of pounds per square inch get unwieldy to write, so American engineers shortened them to ksi, the kilopound per square inch. Wikipedia notes it is used mostly in materials science, where tensile strength runs to large numbers of psi. One ksi is 1,000 psi, or about 6.895 MPa; NIST gives 6.894757 MPa.
Steel specifications, reinforced concrete and structural design are the typical uses. A concrete compressive strength of 4 ksi corresponds to about 27.6 MPa, and a bolt rated at 60 ksi would be roughly 414 MPa. The related unit Mpsi, a million psi, is used for elastic moduli of metals, so steel at 200 GPa is about 29 Mpsi. Metric countries write all of this in megapascals, which is why engineers working across borders keep the factor 6.895 close at hand.
1 kilopound per square inch = 6,894,757.293 pascals (approximately).
Sources: Wikipedia: Pounds per square inch; NIST SP 811, Appendix B.8; Wikipedia: Pascal (unit)
Standard Atmosphere (atm)
Exactly 101,325 pascals, the average pressure of the atmosphere at sea level.
A column of mercury about 76 cm tall was Torricelli's measure of the air, and the standard atmosphere began as exactly that: the pressure of 760 mm of mercury at 0 degrees Celsius under standard gravity. It was used as a reference for physical and chemical properties, and the Celsius scale set 100 degrees as the boiling point of water at that pressure.
In 1954 the 10th CGPM confirmed the standard atmosphere as exactly 1,013,250 dynes per square centimeter, which is 101,325 pascals, a definition that no longer depends on the properties of any substance.
In practice one atmosphere is about 1.01325 bar, 760 mmHg, 14.696 psi or 29.92 inHg, and roughly the pressure of 10.33 meters of water. Chemistry splits on it: until 1982 standard temperature and pressure used 1 atm, but that year IUPAC recommended a standard pressure of exactly 100 kPa instead.
1 standard atmosphere = 101,325 pascals (exactly).
Sources: Wikipedia: Standard atmosphere (unit); Wikipedia: Atmospheric pressure; Wikipedia: Evangelista Torricelli
Related conversions
- Standard atmospheres to kilopounds per square inch (reverse)
- Kilopounds per square inch to pascals
- Kilopounds per square inch to kilopascals
- Kilopounds per square inch to bars
- Kilopounds per square inch to PSI
- Pascals to standard atmospheres
- Kilopascals to standard atmospheres
- Bars to standard atmospheres
- PSI to standard atmospheres
- Hectopascals to standard atmospheres
- Megapascals to standard atmospheres
- Millibars to standard atmospheres
- Torr to standard atmospheres
- Millimeters of mercury to standard atmospheres
- Inches of mercury to standard atmospheres
- Gigapascals to standard atmospheres
- Millimeters of water to standard atmospheres
See all pressure units.