contact strips are obtained by segmenting a secondary strip of contacts fabricated from a metal ribbon in which openings are formed with an original regular pitch to form a discontinuous central strip of blades . each blade is twisted to produce a primary contact strip . the method further includes pleating the primary strip and a hardening heat treatment , and begins with the following operations : the ribbon is metal - plated on both sides to cover at least the central strip with a layer of a metal that is a good electrical conductor , openings are formed in the ribbon , and each blade is twisted . it then includes the following successive operations : the primary strip is pleated , the hardening heat treatment is then applied to produce the secondary contact strip , and the secondary strip is segmented into a plurality of contact strips .