Fireline Braided Bead Thread. Diameter: 0.008". Length: 50 yd. spool. 6lb test/ Size D. Smoke Gray. Fireline is a pre-waxed braided cord consisting of gel-spun polyetholine which is known as the strongest fiber per diameter ever created. It has an unbelievably high tensile strength and has been recommended in numerous how-to articles on beadworking. It will fit a #12 English beading needle.