For the Jewellery maker drilling is a process that enables many other processes. Piercing and riveting begin with drilling a hole, and drill bits can be used to create pattern and texture. When it comes to the flex shaft, drilling may seem to be the simplest of tasks, but there's more to the story than it first seems.
First, let's define our terms. We often say drill to define the whole assemblage, but to be precise the drill holds and spins the drill bit. The drill bits that we use in the studio are most commonly made from high-speed tool steel, which is harder and lasts longer than other common drill-bit materials, such as tungsten vanadium steel. There are also carbide drill bits, which are very hard, very sharp, and very brittle; these are special occasion bits for use when you need to cut harder materials. Diamond drill bits, which are steel shanks plated in industrial diamond grit, will cut anything.
When we think of a drill bit, it's probably the common twist bit that comes to mind. A twist bit is a steel shaft with grooves that begin hallway up the shaft and end at the tip. The base, or shank, is the lower ungrooved portion.
As with cutting tools like files or gravers, it helps to think of a drill bit as a chisel. In this context a file would be a series of small chisels, each lined up after the other. The tip of a drill bit has two opposing chisels with cutting edges that face each other and cut as they spin. A drill won't cut in reverse; like a file the chisel tips cut when pushed into the metal but not when dragged in the other direction.
On a twist drill bit, these chisel tips are called lips, and the grooves that spiral around the shaft are called flutes. Flutes don't really cut; their primary job is to evacuate swarth, the cut material. If the swarth isn't removed it will jam up and bind the bit causing it to snap.
Most drill bits have a shank that's the same diameter as the rest of the bit, so an adjustable handpiece is required to accommodate the different sizes. For those who love their quick release style handpieces, there are choked drill bits. The various shaft sizes of these all emerge from a 2.38mm shank, the common size used for flex-shaft accessories and for the collets of most quick release handpieces. Handmade Rings are where these particular bits come in handy.
First, let's define our terms. We often say drill to define the whole assemblage, but to be precise the drill holds and spins the drill bit. The drill bits that we use in the studio are most commonly made from high-speed tool steel, which is harder and lasts longer than other common drill-bit materials, such as tungsten vanadium steel. There are also carbide drill bits, which are very hard, very sharp, and very brittle; these are special occasion bits for use when you need to cut harder materials. Diamond drill bits, which are steel shanks plated in industrial diamond grit, will cut anything.
When we think of a drill bit, it's probably the common twist bit that comes to mind. A twist bit is a steel shaft with grooves that begin hallway up the shaft and end at the tip. The base, or shank, is the lower ungrooved portion.
As with cutting tools like files or gravers, it helps to think of a drill bit as a chisel. In this context a file would be a series of small chisels, each lined up after the other. The tip of a drill bit has two opposing chisels with cutting edges that face each other and cut as they spin. A drill won't cut in reverse; like a file the chisel tips cut when pushed into the metal but not when dragged in the other direction.
On a twist drill bit, these chisel tips are called lips, and the grooves that spiral around the shaft are called flutes. Flutes don't really cut; their primary job is to evacuate swarth, the cut material. If the swarth isn't removed it will jam up and bind the bit causing it to snap.
Most drill bits have a shank that's the same diameter as the rest of the bit, so an adjustable handpiece is required to accommodate the different sizes. For those who love their quick release style handpieces, there are choked drill bits. The various shaft sizes of these all emerge from a 2.38mm shank, the common size used for flex-shaft accessories and for the collets of most quick release handpieces. Handmade Rings are where these particular bits come in handy.
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