The KSI is used to express the ultimate tensile strength (UTS) of any material. Steel with a UTS of 60,000 pounds per square inch could also be expressed as 60 KSI, with the "K" representing kilo or thousand. Sometimes, the UTS can be found expressed in Mpa or megapascals.
To convert Mpa to KSI, the Mpa must be multiplied by 0.1450377. The UTS is an intensive property, and therefore its value does not depend on the size of the test specimens. What does effect the UTS is the way the mild steel is treated, whether it has been hot or cold drawn or hot or cold rolled, or received annealing or quenching heat treatments.