The two turn blood knot is a simple variation of the blood knot that joins two very different line diameters, like twenty-pound to ten-pound or a 2X to a 4X tippet, using two turns on the heavy side and four or five on the doubled light side. I got it out of Rob Fordyce's tarpon book and it is one of my favorite knots for tying dissimilar lines together. In this How 2 Tuesday I walk through exactly how to tie it, when to reach for it, and why it is so strong.
Watch and listen now: press play in the player above and follow along.
The two turn blood knot is a variation of the standard blood knot used to join two pieces of line that are very different in diameter, like twenty-pound to ten-pound, or a 2X to a 4X trout tippet. The trick is using two turns on the heavy side and four or five turns on the doubled light side, which evens out the knot and makes it grip securely. I got it out of Rob Fordyce's tarpon book, and it has become one of my favorite knots for tying dissimilar lines together.
Use it any time you need to join two lines that are too different in size for a standard blood knot to hold cleanly. That comes up when you do not have the intermediate sizes to step down gradually, like jumping from twenty-pound to ten-pound, or when you want to add a heavier shock tippet, such as putting twenty-five-pound on the end of ten-pound line. In trout fishing it is perfect when your leader has shrunk down to 2X and you need to get to 4X without building a whole new leader.
Take the lighter line and double it over, no bimini needed, just so you have two strands instead of one. With the heavy line, make two turns. With the doubled lighter line, make about four or five turns. Then pass it back through the middle the same way you would tie a standard blood knot with single strands. The result is two turns of heavy line on one side and five turns of doubled light line on the other, and it cinches into a very strong, compact knot.
Because matching the turns to the line diameters balances the knot. A heavy line is stiff and does not need many wraps to bite, so two turns is plenty, while the lighter line needs more wraps and the doubling adds strength so it does not cut itself or slip. A standard equal-turn blood knot struggles when the two lines are very different, but distributing the turns this way lets the knot seat evenly and hold under real pressure.
Yes, it shines in trout fishing. As your tapered leader gets shorter through the day you often end up needing to jump from something like 2X straight to 4X without the in-between sizes on hand. Instead of pulling out a whole new tapered leader, you double the 4X over, tie a two turn blood knot, and keep fishing. Building a fresh tapered leader is the ideal fix, but in that on-stream pinch this knot gets you back casting in seconds.
It is, and I use it on a lot of my tarpon leaders by choice, not just in a pinch. It came out of Rob Fordyce's tarpon book for exactly this reason, joining lines of very different diameters with confidence. It is easy to tie and exceptionally strong, which is what you want when a big tarpon is testing every connection in your rig. For me it has earned a permanent place in how I build leaders for serious saltwater fish.
I came across the two turn blood knot in Rob Fordyce's tarpon book, and it solved a problem I run into constantly, joining two pieces of line that are just too different in size for a normal blood knot. Whether I am stepping a trout leader down or building a tarpon leader, this is the connection I trust. It is easy to tie and exceptionally strong, and once you have it in your hands you will use it everywhere. I show the whole thing in the episode, so press play in the player above.
Here are the steps I walk through. Watching the video above makes it click fast, but here is the sequence.
Watch me tie it step by step in the video above.
The two turn blood knot earns its keep whenever you are joining lines that are too different to step down evenly. Maybe you only have twenty-pound and ten-pound with nothing in between, or you want to add a twenty-five-pound shock tippet to ten-pound line. In trout fishing it is when your leader has shrunk to 2X and you need 4X without the in-between sizes. I give the real-world situations in the episode, so press play in the player above.
The reason this knot holds where a standard blood knot fails is all in the turn count. The stiff heavy line only needs two turns to bite, while the lighter line needs more wraps and the doubling adds strength so it does not slip or cut itself. Balancing the turns to the diameters is the whole secret. I explain why that works in the episode, so press play in the player above.
This is one of those knots that quietly becomes part of how you fish. I use it on a lot of my tarpon leaders by choice, not just when I am in a pinch on the water, and it has never let me down on a big fish.
Watch the video, tie a few at home until your hands know it, and you will have a fast, strong fix for dissimilar lines whenever you need it. You can also find it at tomrowlandpodcast.com and saltwaterexperience.com. Press play in the player above.
How 2 Tuesday is my weekly series where I break down one fishing skill at a time, from knots and casting to gear, tactics, and the habits that make you a better angler. Watch and listen to every How 2 Tuesday episode from Tom Rowland.
blood knot · Rob Fordyce · tarpon leaders · trout fishing · fluorocarbon · monofilament · tippet · shock tippet · fishing knots · How 2 Tuesday · Saltwater Experience
I'm Tom Rowland, a professional fishing guide based in the Florida Keys, host of the Tom Rowland Podcast, and the longtime host of the Saltwater Experience television show. On the podcast's How 2 Tuesday series I break down one practical skill or lesson at a time, from fishing technique and gear to the habits that make you a better angler, in short, focused episodes you can put to use right away.
Subscribe to get the latest episodes, show notes, and exclusive content delivered straight to your inbox.