摘要:
An invar type alloy wire has areal ratio of carbide existing at grain boundary of the wire in processed final wire size of at most 4 %, or average grain size in transverse direction within a range of 1 to 5 µm, and hence it has superior twisting property.
摘要:
There is disclosed a method of stranding together a plurality of strands (7) of sectorial cross-section around an optical fiber unit (2) which serves as a central wire material. First, a rigid type stranding machine is used to impart spiral twist to each strand (7). Subsequently, the twisted strand (7) is heat-treated to remove its strains. These strands are then fed to a planetary type stranding machine which provides planetary motion in which they make orbital rotation around the optical fiber unit (2) without making own-axis rotation, whereby they are stranded together on the optical fiber unit (2).