represents the yield strength of the bolt. This number rep- resents how much stress the bolt can take before it is un- able to return to its original shape without damage. The second number represents a percentage rating. For ex- ample, a 10.9 bolt has a tensile strength of 1,000 MPa (145,000 psi) and a yield strength of 900 MPa (90% of 1,000). A 10.9 metric bolt is similar in strength to an SAE grade 8 bolt.