Chesterton 329 Stern-Lon® is square-plait-braided to provide an unusually flexible, formable packing. The base fiber is a long-fibered, roved flax of the highest quality. 329 is graphite-free to avoid galvanic corrosion on shafts.
During production, 329 is first impregnated with concentrated PTFE dispersion to promote non-flowing lubricity and to retard degradation. This is followed with a plasticizing "break-in" lubricant which assures compressibility, flexibility, and good packing-to-shaft contact. Large sizes need not be hammered into place. Finally, to minimize frictional attrition, a finely divided fluorocarbon powder is embedded into the surface of the packing. Chesterton 329 produces little or no shaft or sleeve wear.