Tensile is
defined as the uniaxial tension until failure measured in pounds per square
inch (PSI). The higher the failure point the stiffer the wire, this is measured
on tensile testing machine. High quality stitching wire has a tensile range of
135,000 to 165,000 PSI. A tensile above 165,000 PSI will wear out parts in your
stitching head prematurely, causing maintenance costs and down time. High
tensile wire can also wear out the knives in a trimmer section prematurely. The
increased hardness of the stitching wire will nick a trimmer section’s knives
more severely when struck during saddle stitcher jams. A tensile below 135,000
PSI will cause the stitching wire to be soft and not properly form a proper stitch.
High
tensile stitching wires are available in the industry, but the cost benefits of
using a high tensile wire with a thinner diameter on thicker applications is
outweighed by the cost of premature wear on stitching heads and trimmer section
knives.
