Abstract: A hybrid cord is presented for use in the reinforcement of elastomers. The hybrid cord is characterized by having a core steel filament, a first layer of one or more nonmetallic filaments which are wrapped about the steel filament in the core, and a second layer of from 4 to 12 steel filaments which are wrapped about the first layer.

Abstract: An apparatus for testing the fatigue of a sample of cord or filament (12) by bending it over a fixed surface (19). The apparatus comprises a tensioner (14), a fixed bending surface (19) and a driving mechanism (24), whereby the driving mechanism (24) causes a non-twisting bending of cord or filament (12) over bending surface (19) while tensioner (14) maintains a constant tension on cord or filament (12). In a method of the invention, a cord or filament (12) is attached to a tensioner (14), the cord or filament (12) is mounted on fixed bending surface (19) and attached to non-stationary roller (20), and driving mechanism (24) is activated to cause a back and forth movement of roller (20), thereby causing filament or cord (12) to bend back and forth over fixed bending surface (19) until it breaks.

Abstract: A hybrid cord which is characterized by