How thick is fishing line?

The thickness of fishing line depends on two factors; the material it is made of and the breaking strength of the line. For monofilament line, made by pulling a plastic compound through a shaping die, lines can be as thin as .15 millimeters (mm) for two pound test and .48mm for 25 lb. Monofilament line has a stretch factor and can increase up to 25% in length when stretched.

If the lines are made of woven Spectra or a similar material, 6 lb. can be as thin as .1mm. This varies by manufacturer. This type of line has very little stretch, sometimes as low as 1/2%. Because of this, reel drags need to be set to a lower limit to minimize line breakage.

Please note that this is an average diameter, at least for the extrusion-process monofilament lines.

Dacron was also used for fishing line and the diameter varied depending on the number of strands woven into the line. Similar to Spectra-type lines, it has little stretch.

Thediameterof the fishing line is usually identified on the packaging of the fishing line.