Harry Bertoia_Diamond chair

I have been researching Harry Bertoia’s Diamond chair for my current project, for which we’re required to carry out a material technical study.  This involves looking at the materials used to make the chair, as well as the manufacturing techniques.  I discovered that the steel rods used to construct the main shape of the chair are still hand bent, to this day, using a mold.  This is due to the fact that there has never been a machine available that can bend steel rods which meets the designs requirements and the cost to invent such a machine would be too high.

I carried out two separate tests with 3mm steel rods.  For the first test I bent the steel rods into the desired shape, prior to spot welding them together, in a grid configuration.  This is how they are put together in the factory, however, where they would be inserted into the supporting frame before being spot welded, I had to handle them freely and attempt to spot weld them together.  I managed this rather clumsily initially.

For the second test I decided to construct the grid of steel rods flat, to begin with.  One they were secured I then used a former mold, in a tree stump, to hammer and shape the grid into a desired shape.  This second method was easier to handle and manipulate, though unfortunately due to hammering, small indentations were left on the surface of the steel rods, which would require sanding out.  In the long run this would be a lengthier and therefore costlier process.

Steel rods spot welded together and hammered into shape using a former mold.