Jo Klieber: do not tighten M5 screws too firmly!
M5 screws tear off sooner than you feel.
It is hard to believe, yet M5 screws generate up to 30 % more tension than M6 screws being tightened with the same torque. Tighten M5 screws only according to the torque value indicated on the product and until your torque wrench indicates the correct value.
0.8 mm thread pitch per revolution; a flat wedge for improved force transfer. The 5 mm diameter makes for a 2.5 cm longer lever that transmits the force and that affects the resistance in the thread.
Conclusion: M5 screws turn slower than M6 screws with the same torque value yet they generate higher tensions within the thread.
1.0 thread pitch per revolution; a steep wedge with less force transfer. The 6 mm diameter makes for a 0.5 mm longer lever that is reflected in the resistance in the thread.
Conclusion: M6 screws turn faster than M5 screws with the same torque value yet they generate lower tensions within the thread.
President Syntace GmbH