Bolts and machine screws are very interesting. One mistake I, an amateur bike mechanic, made for years was not greasing bolts properly before assembly.
It sounds counterintuitive but without grease a bolt (or machine screw) will bind early with a high torque well before it is correctly tensioned lengthways. The torque is just a proxy for the tension and it is this tension which is needed to fasten your components together as intended.
The grease means that when the torque to turn the bolt reaches the correct value then the bolt is also under the correct tension instead of being because it got stuck in the thread half way.
It sounds counterintuitive but without grease a bolt (or machine screw) will bind early with a high torque well before it is correctly tensioned lengthways. The torque is just a proxy for the tension and it is this tension which is needed to fasten your components together as intended.
The grease means that when the torque to turn the bolt reaches the correct value then the bolt is also under the correct tension instead of being because it got stuck in the thread half way.