Last night I removed a wire nut from 4 wires that I spliced together. I never noticed before but the wire nut actually cuts into each wire about 1/32". I thought maybe it was just that style of wire nut but I tested it out again with a different type and had the same result.
I understand this is how the wire nut stays connected, but I am just curious why this is not bad. Everyone always talks about being careful not to nick wires when stripping them. Aren't all of these little cuts bad for the connection?
Actually, those "cuts" make sure the wire has good contact with the wire nut, and that way the wire nut itself becomes an additional electrical path besides just forcing the wires to touch each other.
I believe the reason that you don't normally want to nick the wires is because to a small degree, the nicks increase resistance to the wire, plus it obviously weakens a part of the wire that doesn't need to be weakened. But here, you're talking about what is going on at the END of the wire and not in the middle of the wire.
If nothing else, think of it this way... sure it's bad, but the benefits far out-weight the negatives at the point of the wire nut.
Yes. High pressure means low contact resistance, and dented wires must have had considerable pressure forcing them together.
A wire nut with an undented wire, with the wire just touching the others, can read 1/2 volt across it while passing 10A. It seems to work but it gets pretty hot and it's mechanically unstable, which may cause intermittent connections.
A nick is not a dent. Cracks can propagate from the sharp corners of a nick, less so from the rounded corners of a dent.