Science Fair Project Encyclopedia
Draw plate
Draw plates are used to draw wire to make it thinner. They can also be used to draw tubes of wire (chenier). They come in many different sizes and shapes: round, square, oval, half-round and hexagonal for example. The plate has rows of holes drilled through it which go down in size by tiny increments. The holes are wider at the back. Wire is annealed and then filed at one end to taper it. The tapered end is inserted into a hole that is next down in size from a hole that it can easily pass through. Pliers or draw tongs are used to hold the tip of the wire and pull it through. The wire can be drawn about 3 times in a row before it needs to be re-annealed. The draw plate doesn't shave the wire off to make it thinner, it stretches it, so you don't lose metal, and end up with a piece of wire that can be many times longer than what you started with. The plate is held in a vice, or on a special piece of equipment where the tongs are attatched to a chain and a handle is turned to move the chain, pulling the tongs and drawing the wire.
In the images the plate is 165mm wide and 35mm high. The largest hole on the front of the draw plate is 2mm in diameter. The plate is 6mm thick. On the back there are only 3 sizes of hole - 5mm, 4.5mm and 4mm in diameter.
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