How many wires can be spliced together?

[LarryFine]

If you don't pre-twist, this one wire in the center of the bundle could be straight and just pull out of the middle of the other 6 that are wrapped around it.

If you want to get really technical, twisting the six outer strands can loosen their grip on the seventh, central strand. When the strands are parallel, they form the 'perfect' six-around-one ring, and all seven circles touch.

But, when you twist the six strands, their cross-sections (relative to the direction of the conductor) become slightly oval, and the ring they form becomes slightly larger, decreasing their pressure on the central strand.

If you twist five strands, not six, around one, you'll find a twist rate where the five outer strands grip the center strand tightly, while also all contacting one another. That illustrates what I'm talking about above.