Leader Straight Talk - What is a Tapered Leader and What Does "X" Mean?

RiverBum Oct 28th 2017

I got an email a couple of weeks ago asking several questions about tippet and leaders. This is a confusing topic, especially for those who may be new to the sport. As I was learning, I remember looking at numbers and Xs and wondering what it all meant, too.

Here's a few quick facts about leaders and tippets that might help you to keep this confusing topic straight.

Tapered Leader

Tapered leaders are the norm in fly fishing. They are quite handy and generally perform much better than flat lengths of leader material of the same diameter, especially in presenting a dry fly well.

Many years ago tapered leaders were either made from braiding a material and gradually using fewer strands as you moved down the leader or they were made by knotting together many sections of leader material that started heavy and tapered down to a finer tippet. These early tapered leaders were made of silk and later nylon monofilament. Some anglers still prefer braided leaders or knotted tapered leaders. Most anglers that still use them today attach a monofilament tippet to the end of the braided leader.

Today, most leaders that are commercially available are tapered nylon monofilament and are created by extrusion or some other similar method. This allows the manufacturer to make a tapered leader out of one strand of nylon that tapers from heavy at the butt (fly line end) to much finer at the tippet (fly end) without knots.

What Does "X" Mean

The number followed by the X that you see on the packaging is actually an indication of the thickness of the tippet only.

The "X" system is a somewhat antiquated method of measuring the leader material and tippet material diameter. Each number followed by X corresponds to an actual diameter.

You can figure the actual leader diameter by knowing that X is equal to 11.

The diameter of tippet or leader material in thousandths of an inch is determined by subtracting the factor number from X or 11. Here are the diameters of the most used X measurements: 8X = .003 inch, 7X = .004 inch, 6X = .005 inch, 5X = .006 inch, 4X = .007 inch, 3X = .008 inch, 2X = .009 inch, 1X = .010 inch, 0X = .011 inch

Measurements of "pound test" that are assigned to most modern monofilament fishing line have also been added to most leaders and tippets.

These do not necessarily correspond exactly to diameter and may be suspect since no real standardized testing is done to come up with these measurements. Line strength also depends on environmental factors and knot strength which varies from brand to brand and knot to knot.

Hopefully this quick lesson on leaders and measurements can help you demystify the X factor and understand tapered leaders and tippets a little better.