These spec brushes are available in black nylon or black hog bristle and in a 13 row staggered 5x4 wide or 12 straight row 5 wide pattern. (ASTM D2486 requires 5x4x13 rows of nylon). The new Gardco brush bristles are secured in a PVC block that is 3.5" long, 1.5" wide and 0.5" thick. The bristles are trimmed evenly to a length of 0.75". Nylon bristles are grade 6/6, 0.012" diameter with a bristle weight on each brush of 5/8±10% ounces.

The bristles are selected as much as possible to be equivalent to the specified nylon. The total weight of the brush is 2.5 ounces, which is 1.5 ounces lighter than current metal-backed brushes. To make up for this difference, a 1/16 inch thick stainless steel plate is provided with each new brush that can be inserted into the brush housing on top of the brush. After a long period of use, the bristles will wear down to below the original length of 3/4". The brush bristles should be measured periodically and if they reach a length shorter than 5/8", we suggest they be discarded. The shorter the bristle, the firmer it is. The firmer the bristle, the harder the run .
Accessories

Specification Brushes - Hair bristle, PVC* 5/4x13 lines