See Straightening and Cutting Machine, Wire.

Wire used to tie together steel reinforcing rod lengths that are embedded in concrete as it is poured. The tied steel assemblies strengthen the concrete section. The steel alloy wire is manufactured to critical specifications for strength, ductility and its bonding ability to the concrete.

See Wire, Bright Annealed.

Used for wiredrawing before the introduction of drawing dies. It was made of-high carbon steel containing a number of holes to suit the size of wire for which it was designed. A wiredrawer’s plate was about 40 mm (1.5 in.) thick with a shank at one end. When all the holes had been worked out, the plate was heated to a red heat and hammered round the holes to close them. After this operation, known as battering, the drawing plate could be used again. Drawer’s plates were also known as wortles after the name of the series of low-alloy tool steels containing several percent tungsten from which they were often made. Still sometimes used for short runs of shaped wire.

A line of equipment using sets of rolls or Turks Head as its basic rolling unit for the manufacture of different shapes of wire. See Turks Head. Also “flat mills,” using opposing rolls and sometimes shapes are drawn through dies.

A solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool. Also called solderless wrapped connection, wrapped connection or wrap post connection.

The process of pulling wire at room temperature (cold) through a die that has a smaller opening, which reduces the cross-sectional area to a re­quired size. Since the wire is deformed plastically in the die because of the pull exerted on it and the taper of the die, there is a limit to the reduction which can be made at one die, according to the amount of pull the wire can withstand without breaking. The physical properties of all metals are altered by cold drawing, so that the end properties required are obtained by matching the drawing program to the state of the initial material and the rate at which this is changed by cold work. In addi­tion, the desired properties can be induced by heat-treatment after part or all of the drawing is completed.

The simplest form of a wiredrawing machine consists of a powered capstan that pulls wire through a single die. As the reduction in size at a single die is limited, most wiredrawing machines have a number of dies and power-driven capstans. The capstans are arranged in sequence with speeds to suit the elonga­tion of the wire at each reduction. There are three basic types: non-slip models, where the capstans run at exactly the same speed as the wire; slip-type models, where the capstans run faster than the wire, allowing the wire to “slip”; and accumula­tion-type machines, which collect more wire on each block than is necessary to feed the following reduction. Many systems are designed to draw one wire, but additional wires can be simultaneously drawn.

Drawing machines in which each block runs at a speed a little higher than would be necessary to supply exactly the amount of wire called for by the succeeding block, thus the amount of wire to be further drawn each block slowly accumulates. On AC-driven machines, the drafting can be arranged so that the elongation between drafts is slightly greater than the speed difference between blocks. Each block is, in fact, a separate machine drawing wire through a die and coiling it up. By means of the waffle arm, wire can be picked up from the running block and transferred to its succeeding block, where it is drawn and coiled through the next die in the series, and so on until the final block is reached. A wide varia­tion of die reductions can be used on these machines without the need for complicated and ex­pensive gear automatically controlling the speed through each die to line up exactly with the elongation of the wire passing through it.

A single-hole wiredrawing machine of very heavy construction capable of drawing all sizes of rod and wire between 9 and 29 mm (.354 and 1.142 in.). Also used for drawing shaped wire and certain materials that need intermediate annealing after only a few drafts. Usually provided with a single die box, but sometimes provided with an additional capstan to produce two drafts.

Wiredrawing machines that typically consist of two to three pairs of shafts with assemblies of three or more capstans of decreasing diameters mounted on each shaft. The dies are mounted between the two cones of the pair and are configured so that the speed of the drawn wire is less than the speed of the capstan. These slip-type machines are designed so that the wire can slip on the capstans. In most machines, the shafts are configured in pairs such that only the leading cone assembly in each pair does the pulling. The other assembly in each pair rotates at the same speed as the pulling assembly and serves to align the wire for entry into the die, Note: in some cone type machines, both assemblies draw the wire, doubling the number of available dies. The capstans on each shaft are sized to match the increase in wire speed as the wire passes through each die. See Wiredrawing Machines, Slip Type.

The double block, an accumulation-type system, consists of a second block mounted above the drawing block and on the same spindle, the drawing block being keyed to the spindle while the upper block is free to rotate on the spindle in either direction. The accumulated wire is stored on both blocks. A pulley transfers wire from the lower to the upper block operates in a similar way to the pulley on the overhead takeoff machine.

A version of the Bull Block machine with two draw blocks mounted on the same shaft. The larger diameter block is generally mounted above the smaller block. Rod enters through a die box on the lower level and is wrapped about the smaller block. It is then conveyed over a guide sheave to a second die box or shaving head on the upper level.

A multiwire system uses the same basic wiredrawing concept to simultaneously reduce the diameter of up to 40 individual wire strands. With an input range of 10 to 16 AWG and an output range of 18 to 44 AWG, the process integrity is totally dependent upon the quality and condition of the copper, dies and lubrication used. The slip-type drawing machine is most commonly used in the industry.

1) Drawing machines in which the capstans run at exactly the same speed as the wire being drawn. Generally used for ferrous wiredrawing. A continuous machine of this type has a finishing block and a number of drawing capstans or cones in line with this. The dies are placed before the first capstan, between each pair of capstans and before the block. Wire passes through dies, where they are also lubricated, around the first and subsequent capstans a number of times until it reaches the finishing block. Since the length of wire increases at each die, successive capstans are run at increasing speeds. 2) Drawing machines that use a dancer between capstans to accumulate any length change so the wire does not slip on the capstan.

An accumulation-type drawing system that has a succession of pulleys mounted on a framework above the machine. Wire passes from the die around a block, over an overhead pulley via a pulley on the waffle arm and on to the next die. A twist is thus imparted to the wire between each reduction. This difficulty is accentuated if for any reason one block of the machine has to be stopped for example when it is full. In this case all preceding blocks must also be stopped and where machines are equipped with an automatic control to stop full blocks this control also stops the preceding blocks. With double blocks only the full block need be stopped.

See Pre-drawer.

Slip-type machines are used for nonferrous wires and finer sizes in ferrous and alloy wires. They are generally wet-drawing, multi-hole machines in which the actual reduction must be greater than the inbuilt speed ratio between successive capstans. Typical slip-type machines are designed to provide at least 3% slip or speed difference at the penultimate block and around 1% additional slip per preceding draft. There is always 0 % slip at the finish or pull-out capstan. The capstan speed should always be equal to or greater than the wire speed at each draft. The hypothetical condition in which capstan speed is less than wire speed is called negative slip, which is an unacceptable condition.

A slip-type wet drawing machine that uses multiple capstans mounted on the same shaft. The individual capstans usually have progressively larger diameters to accommodate wire elongation.

Systems in which the wire takes the shortest path from one die round the block and straight into the next die. While the machine is being threaded up, the torque developed by each motor is adjusted until it is just sufficient to pull the wire through the die and in addition to provide a little extra pull through the wire itself to assist in turning the preceding capstan. This extra pull, known as “back pull,” ensures that the wire passes straight into each die, which is an important consideration, especially when drawing thick wires. The capstans are tilted in the direction of drawing to enable a substantial number of turns to be taken around each one and to permit the wire to run through the die to the bottom of the following capstan in a straight line.