Fly Fishing Leaders Chapter 2

September 23, 2022

Today we're going to dive a little deeper down the leader rabbit hole.   Before we do so let's do a quick rehash on leaders and their purpose.  In our first piece we 

covered that at the most basic level, a leader is a piece of fishing line designed to connect the thick, colored fly line to a fly. 

As you know, some fly designs are heavier than others, no fly will generally be heavy enough to create the kind of kinetic energy you need to pull the line out as happens with a spinning outfit. The weight of the fly line itself does that. In a proper cast, you generate that energy by forming a moving loop with the line in the air, with the rod aimed in the direction you want the line to go, and at the very end of the cast, that energy has been dispelled when the fly lands on the water.

In essence, While the heavier fly line provides the weight necessary to complete a fly cast, the leader serves as a thin, clear connecter to the fly to avoid spooking fish. It also allows for clean unfurling of the line at the end of each cast.

We're going to take a look at how leaders are built.  This includes their overall construction, their diameter, typical materials, and the sections or components.  We'll build on this in future articles on how these different characteristics are evaluated to pick the right leader for a fishing situation and / or a fly.  So without further adieu...

Leader Construction

Most leaders you'll find at the store are tapered in thickness from one end to the other. The thick end, or "butt section," is attached to the fly line and provides stiffness and strength to the top of the leader. The thinner end will attach to tippet and ensures a more delicate presentation of the fly.

For a smooth transition from fly line to leader, it is important that the butt section be the right size.  Leaders with butt sections that are too small or too large a diameter will tend hinge, jerk, or fail to lay out smoothly. In general, leader butt diameter should be approximately two thirds the diameter of the tip of the fly line.  For normal trout fishing, leader butts should be .019-.023".

The fly fishing tippet is the lightweight portion of material at the end of the leader that will be attached to the fly.  Using the lightest, yet strongest, tippet possible without having the fish notice it is the key here.  This is where you can keep the same leader section attached, but change your tippet size depending on the nature of the fishing you are doing and the situation at hand.

The X System

The ‘X’ rating system for fly fishing leader and tippet is confusing at first, but doesn’t need to be.  I’d like to touch on this a bit to help relieve some of the confusion that many newcomers to fly fishing have with fly fishing leader and tippet material.


Manufacturers use a simple rating system, denoted by the ‘X’, that describes the breaking strength and diameter of the fly fishing leader and tippet material.  The typical scale that these run on are a range from 03X down to 8X, with 03X being the thickest and strongest and 8X being the thinnest and lightest.  So basically the ‘X’ size of leader determines how strong and how thick or thin the leader and tippet are.

Here’s a simple chart showing typical fly fishing leader and tippet sizes on the ‘X’ Rating scale:

Tippet Size Diameter (mm) Breaking Strength (lbs) Recommended Fly Size
8X .003" 1.75 22-28
7X .004" 2.5 18-24
6X .004" 3.5 16-22
5X .006" 4.75 14-18
4X .007" 6 12-16
3X .008" 8.25 6-8
2X .009" 11.5 4-8
1X .010" 13.5 2-6
0X .011" 15.5 1/0-4




There are 2 main types of tippet that are categorized by the material used in each. The first is Monofilament, which is generalized by lower poundage, lower prices, and a diverse range of uses for most species. The second is Fluorocarbon, which is typically stronger, more expensive, and is reserved for occasions that require a more durable line.

Monofilament is the most commonly used in fly rigs. Think of it as the “go-to”, the fly line you use in every situation.

Quick note....take care not to leave monofilament out in direct sunlight as UV rays will deteriorate it. I would suggest that before each fishing trip, take a few moments to inspect your line for any kinks, knots, and cuts that seem to compromise the strength of the line. Even more surprisingly, much like humans tippet can even become bruised. This is usually when it takes a beating against rocks and turns the areas a foggy white.

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