Generally, standards for tyre pressures use SI units, with tyre inflation pressures referenced in units of either kilopascals (kPa) or bar1). However, there are certain regions and countries around the world where customary or Imperial units are still used, with tyre inflation pressures referenced in pounds per square inch (psi). This Technical Report recognizes the need in those regions to establish standard equivalencies between the different units of tyre inflation pressure in the interests of promoting standardization.
PD ISO/TR 29846:2008 contains assigned kPa values for whole psi values in the range of 1 psi to 152 psi, for inflation pressures for use in certain regions of the world that require the use of psi for inflation pressures.
These equivalencies are intended for future applications and do not apply to past practices. The equivalencies given have been established for the tyre industry, but may be applicable for other applications, as appropriate.
ISO/TR 29846:2008