Well learnt something from Jason Gould at the Acoustica Show today. He told me that both the internal screws and outer cover (lite and fat versions) should be tightened down to 0.5Mm. He believes you can hear the difference, and any tighter introduces strain which can be heard.
He also mentioned that the screws were particularly designed to go across the whole cable rather than pierce the middle
Now you know!
Nurse!
They still split the strands Iād not have any of them without ferrules fitted.
As for hearing the difference. 
Tighter negates the need for extra power supplies.
You should all get screwing!
Iād rather screw than be screwed. 
One for a separate thread I suggest.
Iāve learned that most people over tighten screws for wall sockets and power cord connectors. Furutech (FI-28 R) specify maximum 150cNm (1.5Nm).
Did naim say 0.5Nm or? Mm?
On Youtube Furutech claims the below so their information differs a bit. So thatās Max / Min 0.8 / 0.3Nm so Naim saying 0.5Nm is pretty spot on. 1 Newton is ~100grammes (gram force).
How much is āhand tightā? Roughly? 
This would be useful
I presume thatās 0.5 Nm? If not 0.5 mm into what? Just curious.
He did say Nought point five newtons per meter.
It would be nice to know what I usually do to tighten a screw, but the torque screwdrivers that measure that low are +Ā£50, so wont be testing
Torque is a crude way of establishing " tightness" of a fastener. 90% of the effort goes in overcoming the thread friction. But, it is easyish to measure.
The correct way would be to measure strain. But that is completely impractical, hence torque.
Itās definitely 0.5 Nm for Powerlines. They use the same setting for both clamping the cable and assembling the body of the plug.
Thatās not a huge amount of torque, so worth re-checking occasionally as Iāve found the screws to be really quite loose on some older Powerlines I tried.
By re-checking Chris, do you mean loosen the screws and reapply the specified amount or is there a way to measure? IIRC, a torque screwdriver tightens to the set calibration. However if, in extreme, the screw is already at 1Nm, then it simply clicks, leaving the setting too high! Likely iām wide of the mark!
Edit - useful advice and one I hadnāt thought of; thatās a few power lines to check then, thanks!
I remember disassembling a UK powerline plug and thought the screws almost felt completely loose. I donāt know if that was 0.5Nm or not. Iām thinking I might buy the Wera 7440 0.3-1Nm.
Is there a tolerance on this 0.5 Nm of torque?
Think about how a fastener works. It relies on the tension (elastic strain) in the fastener to compress something. If this compression (or fastener tension) is lost, things can fall apart or simply not work.
In order for this ādesignā to be maintained, the screw would require disassembly and re-torquing at a frequency. Every month, year? When the sound changes? And, are people really going to do this? Plus, youāll need a calibration certificate for the torquing device to be confident that the correct torque has been applied.
I think you will find there is a lot of intolerance about such detail when talking HiFi 
But no, that was all I was told
Agree!
When we torque up screws on spacecraft, they normally stay torqued for for 15 yearsā¦
although TBF, nobody has ever gone out to Geo orbit to check 
I would just try the correct setting first and then it either needs a bit more, or not.
If youāre starting from an unknown state, where you think there could have been overtightening, of course you can back the screw off first.
I use a little Seeley digital torque driver which was quite cheap and does from 5Nm down to 0.05Nm.
Surely, all this means is ādonāt pierce the insulationsā. That makes (common sense). Distinguishing between torque values which do not cause this; Iāll keep my thoughts to myself!
Shouldnāt be any insulations in the screw zone.
