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11 December 2009

Archives August 2008 : Tool of the Month

Tool of the Month : Drawplate

I recently began an apprenticeship with a local jeweler and goldsmith and have been working with many tools I never thought I would ever touch, except maybe to unpack from a box and place on a shelf. A few weeks ago, I was asked to draw down some gold wire using a draw plate. Typically, the suggestion of using a draw plate immediately would stir a reaction of disgust and plain laziness. "Why in the world would I need to draw down my wire, when I can just buy it in the gauge I need?!" I decided to keep an open mind and try it as I was curious to see how difficult it REALLY was. I annealed the wire, filed a point on one end and started pulling the wire through the draw plate. It was a breeze, and, I can't believe I'm saying this, fun!

A drawplate is a bar of hardened steel with holes of decreasing size. Each hole is shaped like a funnel, having the larger opening at the back end. Typically a drawplate will have 20 to 30 holes with sizes ranging within a 2 to 3 millimeter span. A draw plate is used in conjunction with heavy duty pliers called draw tongs that have a coarse jaw and a curved handle for a strong grip.
Draw plates are extremely versatile. They are typically used for reducing round wire to the size you need, but they also:
  • reduce the outside diameter of tubing (this also makes the tubing walls thicker, which can be especially advantageous in tube setting).
  • aid in making head pins and rivets.
  • draw round wire into square or any other shape you can imagine (this also works for tubing).
Also, if you don't have half-round wire, you can fold your round wire in half and draw it through a round draw plate, and volia! You now have half round wire!
image courtesy of : http://handmadecontemporaryjewellery.com

Draw plates are available in a multitude of shapes. The most common shape is round, however; JFF also carries square and half-round. We can special order drawplates in other shapes as well.
The quality and price of drawplates vary drastically. The best quality drawplate is made of hardened steel and has A quality tungsten carbide inserts in the holes. The A quality tungsten carbide has a high polish finish and leaves the wire shiny and smooth after each pass through the draw plate, however; a tungsten carbide draw plate is expensive (upwards of $120). Be careful when purchasing tungsten carbide draw plates, as there are many imitators with more attractive price tags. These are not finished to a high polish and have pits and will cause unwanted problems.

A hardened tool steel draw plate is also a good choice, but after the drawing process, the wire is usually dull. It is also more difficult to draw the wire through the plate than the aforementioned tungsten draw plate. The tool steel drawplates range in price from $50 to $100.

Steel draw plates that have not been hardened, or are not tool steel, are not recommended for reducing the size of wire, because the hole will actually deform during the drawing process. They are, however; excellent for making head pins and rivets. These steel draw plates are priced around $15.

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