GB1122803A - Improvements relating to drawn wire - Google Patents

Abstract

A method of manufacturing a mono-filament drawn wire the cross-section of which increases progressively along its length comprises drawing a length of wire through a die whose throat is susceptible to progressive wear by the passage of the length of wire through it, the material of the die being at least as susceptible to wear as the material of the wire, whereby the cross-section of the die increases progressively and substantially through wear as the length of wire is drawn through it. In an example describing the production of a high-tensile high-carbon steel wire 65,000 ft. long the wire is drawn through a high-speed steel die. At the beginning of the operation the wire leaves the die with a diameter of .030 ins. and at the end of the operation the die-wear is such that the wire diameter is .064 ins. The rate of die-wear is accelerated, by comparison with known processes, by using a die in which the throat is of reduced axial length. The rate of die-wear can be controlled by using an abrasive-carrying lubricant, measuring the diameter of the wire leaving the die and varying the abrasive content of the wire to produce the required taper. The filaments may be used to form a multi-strand cable, the filaments all tapering in the same direction along the cable and all extending over the whole length of the cable.