STEEL CORD FOR REINFORCING RUBBER PRODUCT

摘要

A steel cord (7) comprises a plurality (from 3 to 27) of component steel wires tightly twisted at a regular pitch P from 5 to 20 mm in the same direction. Each wire has a diameter d from 0.1 to 0.4 mm. At least one of the wires (1) includes a spiral portion having a spiral pitch P1 from 0.1P to 0.7P and a spiral diameter d1 from d + 0.02 mm to d + 0.2 mm. At least one other wire (2) includes a straight portion. At any cross section of the cord, 25 to 66% of the wires are spiral and the other wire(s) is (are) straight. The stretch of the cord under a load of 5 kg is from 0.10 to 0.40%. A method of an apparatus for producing such steel cord are described and claimed.