X/0 vs. Denier

Fly Patterns
1

I’m trying to make sense of the X/0 sizing for thread versus the denier sizing method. I have Uni’s Big B thread, which I believe is a 40 denier, and I’m wondering how it compares to 6/0 Uni. It looks like it’s about twice the size of 6/0 and actually makes really strong furled leaders. Can anyone help me get my head around this? Simple minds want to know.

2

Brought to you through the magic of the internet

http://www.flytyingworld.com/classroom/95/1170-Threads.html

Or

http://www.flyfishusa.com/fly-tying/thread.htm

Or

http://mvff.tripod.com/Reference/Denier.pdf. (i printed this one)

Hope it helps

3

This may help:

http://mvff.tripod.com/Reference/Denier.pdf

Regards,
Scott

ooops, looks like maodiver beat me to the punch

4

Suspect you have the denier measurement wrong fro the Big Fly thread. My searches indicate 400 denier, not 40. According to the Uni-thread site (which is also wrong) it is 4X stronger and 4X thicker than 6/0. Perhaps that’s the source of the confusion? Good luck figuring out proportions. Empirical testing (aka just try it) is probably your best bet.

5

Uni Big B is 440 denier not 40. Uni 6/0 is 135 denier. See the chart in this Chris Helms article. http://www.swtu.org/pdfs/fly_tying/Threads.pdf

6

Thanks you guys. My mind can rest now. I have a few spools of Big Fly and I don’t like it for anything other than furled leaders.