I am currently building a blank from china and the labeling says the blank is 10 lbs. How does that translate to fly wgt. Is there a chart or formula for that conversion.

With the experiences we've all had with Chinese products and the instructions and product information, perhaps they mean a 10 wt. blank. Lb. vs Wt. seems reasonable to me.

If you're talking about monofiliment lb test, it does not relate. Fly lines are "weighted" in the sense of their taper, diameter, material, etc. It is possible to relate casting lure weight to fly line weight, sort of, but due to their being no standard for what constitutes any given line weight rod, the best that will do is put you in a remote ball park much of the time.

.......................................

CCS the blank?

A lot of the steelhead rods I've built with a line rating of 8 to 12 lb. line, have CC'd around an ERN of 12 as an average.

Robert

If your question is what weight fly line equals to a pound test rating, it does not work that way. There are charts to predict what fly line weight might work for a blank, but you need to know more than you included in your post. More specifically, if you know or determine the CCS numbers for your blank you can then get a handle on the fly line weight that might work. See the CCS information to the left and this link [common-cents.info].

An alternative is to tape on guides, do a static load test and adjust the guide locations as needed, then test cast various line weights until you find the one or two that work best.

Building up a fly rod on a spinning or casting rod blank can be done (a blank is a blank) but unless you've a depth of experience with the blanks to be used or are prepared to do some research to quantify your blank's properties, trial and error is the alternative. And even if you have or obtain the CCS numbers you will want to test cast the rod with the indicated fly line weight just to be sure.

Jay has it right, start with CCS.

"Ten pound test" monofilaments usually test 12 to 15 pounds breaking strength, while fly lines usually test about twice that.

Robert,
If you provide the butt dia, tip dia, blank length, weight and material I can give some direction for an approximate fly line weight.

Gene

Butt dia. Is 9mm/.355 . Length is 7'9".

Robert,
Certainly not a 10 weight.
More likely a 6-8 weight fly rod, based on the info given.

Gene

Digital electronic scales are relatively cheap - less than $25. It's quick and easy to measure and weigh the first 30 feet of fly line to determine the AFTMA "weight" of a fly line and the matching "weight" fly rod it is best suited for. Be advised, the AFTMA is based on an integrated "shooting head taper" configuration: 30 feet of weighted head, 60 feet of running line. Many fly lines made in the past 30 years have weighted tapers 40 or even 50 feet long, designed for fly casters who can false cast and cast farther than thirty feet.