Making Sense of X-Ratings


The more astute amongst you may have noticed that our Platinum tapered leaders are sized using an “x-rating” for the tip not a breaking strain, this is not issued by the Film Censors but is an archaic and very useful way of describing the diameter of leaders and tippet, expecially when choosing which to use with a particular fly. Without getting too technical it refers to the number of progressively smaller holes through which (in the “old” days) gut was drawn to reduce the diameter, so 3x was drawn through three holes, and 4x one more hole. Many think that it has no place in modern angling but this is far from true, in fact it is widely used by US anglers.

Some anglers are obsessed with breaking strain and stress themselves out when a tapered leader made of different materials might have a greater breaking strain on the fluorocarbon tippet than a middle section of mono. The reality is that, as long as it is enough, breaking strain is irrelevant and anyway, a 2lb fish doesn’t pull 2lbs, unless you try to lift it out of the water by the leader! The most important thing is that the diameter of the tippet suits the size of  fly being used. Many anglers are aware of this but wrestle with comparing diameters in inches and millimetres and breaking strains in lbs and kg and then relating this to the flies being used until their brain hurts. Each “x” number refers to a fairly precise diameter and this makes life easy for us.

Actually, by far the easiest way of choosing the most appropriate tippet is just to divide the size of the fly by 3 to get the best x-rating. So for a No. 12 you need a 4x tippet and for a No. 18 you need 6x, for a No.14 or 16 5x is the best. This will mean that the tippet is not so thick that the fly appears “wooden” and not so thin that the fly twists the tippet up when being cast. The sky will not fall in if you go a size up or down but this method just gives you the best option.

You can also easily mix materials to make a tapered leader by just reducing the diameter of each section using the system; so maybe a 1x mono butt, 3x fluoro middle and a 5x fluoro tippet. With our knotless tapered leaders you can add droppers using a Surgeon’s (Water) Knot and material of the correct diameter rather than cutting the leader and using the tag end of the knots, most of which will be too thick for the fly.

For those still obsessed with breaking strain the table below might save on aspirins!

Platinum Tapered Leader Breaking Strains (at the point).

Leader X Rating B.S. lbs Butt mm Point mm
9’ 2x 7.8 0.229
9’ 3x 6.8 0.203
9’ 4x 5.4 0.178
9’ 5x 4.3 0.152
12’ 2x 7.8 0.56 0.229
12’ 3x 6.8 0.53 0.203
12’ 4x 5.4 0.53 0.178
12’ 5x 4.3 0.51 0.152
12’ 6x 3.0 0.43 0.127
15’ 3x 6.8 0.203
15’ 4x 5.4 0.178
15’ 5x 4.3 0.152