Was crucifixion rare?

[M. Demetrius]

The interesting things to me from that nail in the link (that's the one I mentioned earlier, but couldn't remember the source, BTW) is that it's a double-headed nail, intended to be more easily removed, but the tip evidently bent around a knot or something inside the upright, so I couldn't be pulled. The source I read way back when said that there was a chunk of wood still clinging to the nail.

Darned if I haven't encountered nails just that tough when deconstructing old stuff. They defy a claw hammer or nail puller. Grr. :?