Fishing Line: The Truth About Breaking Strength


Ken Schultz

Today there’s a number of excellent thin-yet-strong lines, most if not all originating overseas, and one common characteristic is that their diameter is thinner than that of conventional lines with the same or similar labeled strength.

Strength is a line characteristic important to all anglers. Manufacturers have been emphasizing strength for decades, frequently in a misleading way.

How much they emphasize strength – and how little anglers understand about this most basic property of line – was brought home to me at a trade show while listening to a manufacturer’s representative discuss his company’s product. Among the prominent features was its high strength, and it was clearly stated that the actual breaking strength greatly exceeded what was marked on the label. The 20-pound product, for example, really had a 34-pound breaking strength, and there was a similar disparity in other categories. This type of misrepresentation happens with many, in fact probably most, fishing lines, and the implications are missed by most anglers.

Labels Don’t Tell the Whole Story

Few anglers understand that the real breaking strength of many fishing lines is not what it is usually stated as on the label. The result is often that they fish with a much stronger line than they need, or that may be preferable for a particular type of fishing or technique.

The most significant drawback to this is an inability to compare all of the performance aspects of lines on an equal footing with each other. Since many lines of the same labeled strength actually break all over the map – one line labeled as 10 pounds may really be 12, another may be 13.5, another may be 15, etc. – you can’t easily evaluate or compare them. Moreover, without doing some testing yourself, you don’t know just how different they are. And if these are compared to a labeled 10-pound line that actually breaks at or near 10 pounds, the former seems inferior, even though in other respects it may be the best of all the products labeled as 10-pound line.

Another drawback is in that murky area of sportsmanship and fair play. Most people use more tackle than they need for the average fish already – using 10- and 12-pound tackle, for example, when almost all of the fish they catch are under 2 pounds. Thus, if they use a labeled 10-pound line that really breaks at 15 pounds, they’re using 50 percent heavier line than they thought. It’s overkill.

Since the strength of some lines is directly related to their diameter, many lines are not only stronger than labeled, but they have a corresponding thicker diameter, which can be a drawback. The larger the diameter the more visible the line is and the more it affects the action or diving abilities of lures. Thinner lines allow lures to act more naturally and to achieve greater depths.

Light-Tackle Use and Records

Fishing with a line that is really what it is represented as is especially important to people who fish with light tackle, who demand a lot from their equipment, and who periodically or perhaps often push their tackle to the limit. It’s also important to those who seek records, but that’s a small number of specialists. However, many casual anglers have been stunned to find that the great catch they made was disallowed from record qualification because testing showed that the line they used was much stronger than labeled.

If you’re concerned about this, especially with respect to potential records, contact the manufacturers and ask them what the wet breaking strength of their product is.