As with all "bends," the figure 8 bend joins the ends of two ropes. After holding a heavy load, the figure 8 bend is easier to untie than most bends (e.g., a double fisherman's bend, ring bend, or water knot). Once you are familiar with tying figure 8 knots, it's easy to remember how to tie a figure 8 bend. Note that the figure 8 bend is a little bulkier than other bends and it takes a little longer to tie and dress.
To tie a figure 8 bend, first tie a figure 8 skeleton knot in the end of one rope. Then take the tail of a second rope, and, as with a figure 8 follow through knot, thread the second rope through the skeleton knot. Dress the knot and leave tails that are at least fist-width (3-4") long.
The "critical point test" (aka "scissors test") requires that if any one item fails, nobody should be injured.
A "bend" is a knot that joins two ropes.
A "hitch" is a type of knot that must be tied around another object.
The "whistle test" requires that if all rescuers let go, nobody should be injured.