[jzeiler]

You really don't need an angle meter as 60 degrees is one flat of the nut, but of course you need to mark it after the 50 Nm. Don't sweat it.

 

[jzeiler]

Trouble with checking a torque value is you can only do it if the bolt or nut is moving, hitting the torque value without movement is meaningless. Your only takeaway is it is a least that but know way to know if it is more than that. Over torque is as bad as under torque.