The blood knot is used for joining two fishing lines together. Popular within the fly fishing community, this joining knot is a great alternative to the double uni knot for those that find it easier to tie.
Use Cases For The Blood Knot
Attaching leader lines to main fishing line.
Can be used to attach main line to backing line.
How To Tie A Blood Knot
Overlap the two ends of fishing line you wish to join together.
Grab the tag end of one line, and wrap it around the standing end of the other fishing line about 5 or 6 times.
Take the tag end and tuck it back between where the two fishing lines first meet. At this point, you've just tied a half blood knot!
Repeat the process with the other end, again tucking the tag end between the two fishing lines, but in the opposite direction.
Pull the two standing ends to tighten and trim the tag ends close to the knot.
Congratulations, you've just learned to tie a blood knot!