DIAMOND WIRE DIES

One can hardly over-estimate the enormous importance of wire to our modern society. Millions of miles of wire are made each year for electrical and other uses. One factory alone makes a million and a half miles each month! Wire is made by drawing metal through a fine hole in a die. Softer metals can be drawn through a fine hole in a steel plate, harder metals through a hole in a carbide plate, but really hard metals or very fine wires produce so much relative wear on the die that only a diamond is hard enough and resistant enough to meet requirements. Wires of copper, steel, tungsten, and so on, can be drawn down to thickness of 1/5000 inch. For such fine wires 1 lb weight of metal can make 1000 miles of wire.

Tire point at issue is that in the rapid drawing of wire (and speed is necessary because of the huge mileages needed), the line die hole suffers wear unless the die is of very resistant material. Wear means, first, irregularity in shape, second, variability in strength of the wire and, finally, ultimate failure.

A diamond die is a high-quality (gem-quality) diamond through which a very carefully prepared fine hole has been drilled. This is by no means an easy operation. To begin with there is still some argument about which is the best direction, but we shall avoid this issue.
The diamond, preferably a rounded dodecahedron, since experience has proved these to be the strongest, is drilled to the shape.
Various drilling methods have been developed. The conventional way is to rotate a fine needle, which at the same time reciprocates up and down, using diamond grit on the tip. The method is slow and requires much skill. In modern methods the needle rotates at the exceptionally high speed of 100 000 rev/min, moving up and down meanwhile 200 times a second. Special ultrasonic vibrating machines are sometimes used.

Much faster drilling is obtained by using what is called an electrolytic method. The diamond is immersed in a liquid ad sparks passed to it from a fine platinum point. The spark drills through the diamond and is capable of producing an extremely fine very circular hole. Times have been reduced from two weeks for mechanical drilling to two hours for electric drilling. A good die is precious and some have been known to last several years of continuous use. If you want to buy diamond wedding bands visit this site.

The new light source, the laser, is the latest tool for drilling diamond. A laser is an optical device which produces an extremely powerful pulse of light energy for a short time, which may be one-hundredth part of a millionth of a second, As a rule, such a pulse produces a very irregular hole in a diamond, indeed it may shatter it completely (the impulse of the shock leads to a cleavage).

If a weakish laser beam is used, then a very fine (irregular) hole can be punched through the diamond and this can thon be used as a leader for mechanical drilling or electrolytic drilling. The method yet awaits development.

This section may be concluded by mention of the fact that diamonds drilled through have successfully been used as very resistant jets for a variety of corrosive liquids. Indeed, they have been used as jets in central heating systems in the U.S.A.