PURPOSE: To obtain the wire drawing direction of a hard steel wire of 0.05-0.2mm finish wire diameter which is limited to about 600m/min wire drawing speed conventionally, at a high speed and with high efficiency.
CONSTITUTION: In a wet slip continuous wire drawing machine, the number of dies is 25-50 pieces, inter-dies cooling is executed by an all sinking type in a water soluble lubricating liquid, and also, in a die-die distance to a fifth die counted from a final die, prescribed cooling length is secured through a drivable capstan of three shafts or more and while preventing aging embrittlement, a hard steel wire of 0.05mm-0.20mm finish wire diameter is manufactured by giving 1500-2000m/min final wire drawing speed, and high percentage reduction working total true distortions 4-6. According to this invention, repeated use of an extra fine wire drawing machine is eliminated, an extra fine steel wire whose mechanical property and twist workability are excellent can be subjected to wire drawing at a high speed, and the manufacturing cost of the extra fine steel wire can be reduced. Also, since the aging deterioration is small, the extra fine wire being excellent in quality, as well, can be offered.
TASHIRO HITOSHI
SATO HIROSHI
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