Everything You Need to Know About Blood Knots

Tying a blood knot can be intimidating, especially if you’re new to fly fishing. But there’s no need to fear! 

This simple knot is easy to master because you don’t need special tools or materials. In this article, we’ll show you how to tie blood ties so you can confidently use them on your next water adventure.

What Is a Blood Knot?

A blood knot joins a monofilament and fluorocarbon (or other types of fishing line) with the same diameter.  

It is a favorite knot among many fly fisherman because it smoothly glides through the rod guide, compared to surgeon knots. It can even join the line to hooks or swivels by passing them through the eye of the fastening point before tightening the ends of the line. 

Expert insight: Although blood knots are for combining two lines together, you should always check first the condition of ropes. If they are already flimsy or brittle, there is a chance that the knot will come loose, regardless of how tight you tie it. 

What Are Blood Knots Used For?

Like other fishing knots such as nail knots, double uni, clinch knots, and Albright knots, blood knots are commonly used in fly fishing because they are easy to tie and offer impeccable line strength.

Blood ties prevent the backing from slipping under tension and make the connection stronger than simply tying a clinch knot over the top. 

You can also use this knot when attaching a tippet to sections of the leader. This is particularly important when using fluorocarbon material as this type of fishing line is less elastic than nylon monofilament.

Expert tip: If you want to make leader connections, you can also use blood knots. 

What Are the Advantages of Blood Knots

Whether connecting fishing hooks and lures or tying two lines together, blood knots have many benefits, including: 

  • Secure and Resilient: The main advantage of blood ties is that they will not come undone easily, making them ideal when tying up a fishing line or other thin materials.
  • Seamlessly Merge Lines Together: You can use blood knots to tie multiple lines together and make them look like one continuous line. This is useful for making fly fishing leaders.
  • Create Tapered Leaders: If you want to make individual leaders for saltwater fishing, blood knots are also excellent. 

What Are the Disadvantages of Using Blood Knots

Blood ties are excellent for joining two lines of the same size. However, they have some disadvantages, including:

  • Difficult to Untie: The more you pull on them, the tighter they get, so it’s hard to loosen them back up.
  • Learning Curve:  You will need to practice tying this knot. If not, it will likely get stuck on the rod guides. 
  • Line Diameters Should Be Identical: The principal drawback of a blood knot is that you should use lines of similar size, or else there is a substantial loss of strength. 

Expert Tip:  Use a double fisherman’s knot instead of blood ties if you tie two lines together that will bear more than 20 pounds of force at any given time.

When to Use a Blood Knot

You should use a blood knot whenever you have two odd pieces of lines but in the same diameter. Using a blood knot is also perfect when you have a tapered leader that you want to connect to a tippet. It is also an excellent choice for tapered leaders and droppers. 

How to Tie a Blood Knot?

diagram showing how to tie blood knot for fly fishing

As mentioned earlier, tying a blood knot is pretty straightforward, even for beginner anglers. The key is making sure that the lines have the same diameter. 

The step-by-step guide below will help you tie blood ties, whether using a blood knot tool or not.

  1. Wrap the right line around the left one five times. 
  2. After wrapping the right line five times, take its end and pass it through the central loop. 
  3. Take the left line and wrap it to the right one. Make five turns too. Each side should be a mirror image of the other. 
  4. Take the end of the left line and pass it through the central loop. 
  5. Take the inner strand of each line and pull to tighten. 
  6. Cut the excess lines. 

Expert Tip: Increase the number of turns from five to seven if you use thin lines. This will increase the strength of the knot. For thicker lines, you need fewer wrapped turns. And, if you are having a hard time inserting the line in the small opening, you can always use a toothpick to tug it through the loop.  

Perfect Blood Knots

That’s it! You’re done. A blood knot is not a difficult knot! Unlike other types of knots, blood knots are sturdy and great if you want to combine odd pieces of line together! Just make sure the lines are similar in diameter for a strong knot. 

Do you have a favorite fishing knot? Let us know in the comments.