The X marks tippet strength!

article and graphics by Bill Byrd, Jr.

Do you understand the X system that has been in fly fishing forever? If someone says to you, "I'm changing to a 5X tippet," what does that person mean? Maybe this article will help.

For a long number of years, manufacturers have used a simple rating system that describes both the diameter and breaking strength of tippet material. The basic scale has run from the heaviest 0X to the lightest 8x, but now 12X tippets are being used in Japan on some very small flies and some very light fly rods including Sage's new TXL 3/0-weights. So I've included some new X-ratings on this table.

In the past some fly fishers have even suggested what size flies should be tied on what X value tippet. You have to use your own head on this issue, but the table below may give you a starting point and some reference.

In the table below if you look at 5X tippets it suggests that 5X tippets could be best fished on a 1 or 2 weight fly rod with size 14 to size 20 flies. It should have a diameter of .006 inches (6 thousandths of an inch). Again this is ONLY a suggestion.


Suggested rod weights, tippet ratings, and flies.


Rod weight X rating tippet diameter pound test suggested fly size

5-7 weight 0X .011 inches 9.0 pounds size-4 to size-6
5-7 weight 1X .010 inches 7.2 pounds size-4 to size-8
3-4 weight 2X .009 inches 6.3 pounds size-4 to size-10
3-4 weight 3X .008 inches 5.2 pounds size-6 to size-12
1-2 weight 4X .007 inches 4.3 pounds size-6 to size-14
1-2 weight 5X .006 inches 3.3 pounds size-14 to size-20
1-2 weight 6X .005 inches 2.1 pounds size-18 to size-26
0 weight 5X-7X .006-.004 inches 3.3-1.2 pounds size-20 to size-28
0 weight 6X-8X .005-.003 inches 2.1-1.0 pounds size-20 to size-28
00 weight 7X-11X .004-.001 inches 1.2-.4 pounds size-26 to size-32
000 weight 8X-12X .003-.0009 inches 1.0-.3 pounds size-28 to size-32

These pound test and diameter values will vary from manufacturer to manufacturer, and with different materials. I have found the hard way that the real test value of some manufacturers leader and tippet materials may vary GREATLY from their labeled or published specifications. Be aware that all tippet values from all manufacturers can be certified by submitting samples to IGFA for testing.