Broached Key
Through my research, I discovered that French shaped stem keys were broached to achieve the desired internal shape of the key stem. I made this key as a proof of concept to determine how easy, or hard, this process would be to employ and if it would be successful. I found that, with this shape, it proved to be relatively simple. The rough key was forged from wrought iron. A 1/8” hole was drilled into the stem as a pilot hole. A series of six broaches, of graduating size, were used to enlarge the hole into the final triangular shape. After broaching, the exterior of the key was trimmed and filed to finish. My plan is to further explore this process and work on larger keys.
I decided to make a series of broaches so that when I was finished I would have a set of the various sizes. Alternatively, one broach could be made and the end could then be upset to enlarge its size. With a basic shape, like a triangle, making a set seemed easy. It may be wiser to make one broach and upset and shape it with more complex shapes, such as a fleur de lis.