The copper and copper alloy stranded wires mentioned in this standard only refers to some stranded wire products in field of electric wires and cables used for electrified railways.They have many specifications and stranding types.According to their different functions and positions installed on overhead contact line system (OCS)for electrified railways，these stranded wires are called in different ways，including catenary，auxiliary catenary，head span wire，upper cross span wire，lower cross span wire，mid anchor wire，stitch wire and dropper.This standard focuses on the requirements on technical parameters and technical performance.For the convenience of description and to be in accordance with the names of products in electric wire and cable industry，the term of /"stranded wires/" is adopted in this standard instead of the railway terms mentioned above.The flexible copper stranded wires used for electric connection in OCS are not included in this standard for being regarded as a general product.