Blood Knot
A slim line-to-line knot for building leaders and joining similar diameter material.
The Blood Knot is the cleaner cousin of the Double Surgeon's. It deserves a full walkthrough before we call it finished.
How to tie it
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1
Overlap the two tag ends by 5 to 6 inches and pinch the crossover between your thumb and forefinger.
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2
Wrap one tag end around the standing part of the other line 5 turns, then bring the tag back to the pinch point and tuck it through the gap at the crossover.
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3
Repeat on the other side with the second tag, matching the wrap count exactly and tucking the tag through the same gap from the opposite direction.
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4
Wet the wraps with saliva so the line slides without burning.
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5
Pull both standing lines slowly and evenly until the two coils roll together and seat against each other.
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6
Trim both tags flush to the knot.
Products visible in the tutorial
These are the items the demonstrator uses on screen. Affiliate links where we have a match in our catalog.
When to use it
- Building a tapered fly leader from scratch out of stepped-down mono sections.
- Joining tippet to leader when both pieces are within a couple of thousandths of each other.
- Anywhere you want a slimmer profile through the guides than a double surgeon's gives you.
- Rebuilding a leader at the bench the night before, when speed isn't the constraint.
Common screw-ups
- Using uneven wrap counts on the two sides — the side with fewer turns slips first under load.
- Cinching dry, which scorches the line and leaves micro-fractures that fail on a hot run.
- Pulling the standing lines hard before the coils have started to seat, which leaves the wraps stacked instead of barreled.
- Tying it with a big diameter mismatch — past about 0.002 inches difference, switch to an Albright or Alberto.
Rigs that use this knot
Alternatives
The quick line-to-line knot for adding tippet or joining similar diameter mono and fluorocarbon.
A compact braid-to-mono or braid-to-fluoro connection for spinning setups.
The slim, high-strength braid-to-leader knot for anglers willing to practice before they need it.
What to tie it with
