Fine wire is drawn through successive diamond or tungsten carbide dies in wet drawing machines, with intermediate annealing to restore ductility. Below about 0.2 mm, diamond dies and oil lubrication are standard; below 0.05 mm, tension control and die quality decide breakage rates.
Fine wire is sold on spools by weight or length, with spool type, traverse and knot-free length specified. Surface cleanliness and freedom from inclusions matter for medical, filtration and conductive textile use.
Producers of ultra-fine stainless wire are few — Japan, Belgium, Sweden, Germany and the United States lead, with China growing fast.