thread.

how many yards are in a skein of cross stitch thread

On a bolt, you can sometimes clean out the thread with a knife or hacksaw blade enough to start the nut and tighten it to reform the thread past the damage. In a hole, they make thread chasers that will recut the the thread. You can just run a tap in the hole and it will usually find the old grooves.

Carefully as not to cross thread the CO plug

Some times needle point is done with a thick yarn, not sure if embroidery yarn is what it's called but there is embroidery thread which is more commonly used in cross stich and making friend ship bracelets.