The helically wound tensile cords are engineered, twisted and chemically set stranded fiberglass material.
They are manufactured with a heavy duty, woven, nylon based fabric tooth covering.Timing Belt, 3M, 6 x 537mm PL, T179 They are manufactured to perform at identical or higher levels than all major US Manufacturerâs belts of the same type. All DURA-SYNC TORQUE timing belts are manufactured using the latest in synchronous belt technology. Timing Belt, 3M, 6 x 537mm PL, T179 D&D DURA-SYNC TORQUE belts meet or exceed USA RMA published ratings levels.