An M5 bolt made of AISI 316L steel reaches 100% of Proof Strength with only 4.5 Nm of torque.

To tighten to 70% of Proof Strength, use a tightening torque of 3.1 +/- 0.2 Nm of torque.

There are two failures: (1) breaking the bolt by exceeding its proof strength, and (2) stripping the thread out of the other part that had the tapped hole.  If the other part is Aluminum, then a low torque will strip the threads. If the other part is 1018 steel, it will take a much higher torque to strip the threads.  This is a separate consideration from the bolt material.