Blood Knot for Fly Fishing
How to Tie the Blood Knot
Blood knot -- (Break Strength 90 -- 95%) Used to join two pieces of leader of same or different sizes. Could be used to join two pieces of 4X together to make a longer leader. Or it could be used to join a 4X piece to a 6X piece of leader. This is a more extreme example. Generally the step down would be only one size. 3 to 4 or 4 to 5 or 5 to 6 and so on.
This knot can be difficult to learn to tie by hand. When starting out a Tie-Fast knot tying tool can be of great assistance.
Steps to tie the blood knot
- Lay the lines parallel to each other. Then twist one end around the other 5 times. Bring the tag end of the twisted line and insert it between the parallel lines.
- Twist the other tag end around the remaining standing line 5 times. Insert the tag end next to the other tag end in the opposite direction. (These tag ends are inserted in the center between the parallel standing lines and in the center of the wraps.)
- Moisten the knot
- Gently pull the standing ends in the opposite directions until the knot starts to seat. Then firmly seat the knot with a quick tug.
- Trim the tag ends off close to the knot.
Graphic of how to tie the Blood Knot

Fly Fishing Knots
Knots for Attaching Fly Fishing Line to Leader
Perfection Loop -Fly Fishing Knot
Double Surgeons - Loop Fly Fishing Knot
Nail Knot Fly - Fly Fishing Knot
Knots for Joining Two Pieces of Fly Fishing Leader
Triple Surgeons Knot - Fly Fishing Knot
Double Uniknot - Fly Fishing Knot
Surgeons Knot - Fly Fishing Knot
Knots to Tie the Fly to the Leader
Clinch Knots - Regular and Improved - Fly Fishing Knots