ksi√in\text{ksi}{\cdot}\text{√in}

kip per square inch root inch

Fracture toughnessexact by definition

One kip per square inch root inch, equal to 1.098843 MPa·√m. It is the fracture toughness unit of North American aerospace and pressure-vessel practice.

Watch out: The conversion factor is close enough to one that the two units are casually treated as equivalent. They are not. Nine percent on a toughness becomes nineteen percent on a critical crack length, because crack size goes as the square of toughness.

1 ksi√in\text{ksi}{\cdot}\text{√in} 1.0988435 MPa√m\text{MPa}{\cdot}\text{√m}

One kip per square inch root inch in every fracture toughness unit

1,098,840pascal root meter (Pa·√m)
1.09884megapascal root meter (MPa·√m)
1kip per square inch root inch (ksi·√in)this unit
1,000pound per square inch root inch (psi·√in)