See
What is the correct name for them and where do I find them? I've googled and amazoned, but there are so many different kinds I can't see the wood for the trees.
I've always tinned the wire strands to (a) make it easier to fit them into the screwed holder and (b) stop the strands from splaying when tightening the screw.
The above cable is off an old Woolworths extension lead.
MM