World Record Line-Class Confusion

I just read a bleating blog comment from a Big Game boat skipper somewhere in the US beefing about the fact that he bought some 20lb rated line, but he said it over-tested by nearly 1lb, i.e. broke at 21lb and was therefore useless for chasing 20lb World Records.

The moan reveals some widespread confusion, and flat-out miss-information, about the breaking-strain line classes as used by the IGFA (International Game Fishing Assoc.) to determine World Record claims.

When the IGFA was set upĀ  they decided that as the organisation was international they would use metric weights for setting line classes – that is the line classes would be set in kilogrammes.

But in the US line classes were described in pounds, and still are. But the nominal US pound rating (called US Customary) does not match the line-class in kilos. For instance the 10kg line-class, is 20lb line in US customary terms, but its IGFA rated class is 22.04lbs. So the line being moaned about above was within class.

So if you are chasing World Records it is usually best to buy ‘IGFA rated line class’ line – that is line that is manufactured to break under, but as close to the line-class as possible – but know that the line is rated to kilogrammes not the pounds often shown on the pack. It should also be remembered that line tested for claims must break under the line class.

Here are the line classes used by IGFA, showing the kg class, US customary, and the actual lb line-class the line will tested under by the IGFA.

Line Class (kg) US Custom (lb) Test (lb)
1* 2 2.2
2* 4 4.4
3* 6 6.61
4* 8 8.81
6* 12 13.22
8* 16 17.63
10* 20 22.04
15 30 33.06
24 50 52.91
37 80 81.57
60 130 132.27

* Also Fly fishing record tippet classes