I have old brass curved tube beads in varying sizes. I want to cut or file some of the outside edge of the curve to expose a little cord inside. Do I use a file, a jeweler's saw? What type of blade or file? Thank you.
If you want a slice cut out of the metal, a jeweler saw would be a good tool to use as it will cut through the metal rather easily. Jeweler's files can also be used to cut out a section of the metal although may require a bit more time. The jeweler's files would be ideal for filing and smoothing the edges of any opening.
If you want a round hole in the tubing, start with a pilot hole. You can create this with either a jeweler's file or a fine drill bit fitted to the flex-shaft of a rotary tool. Successive drill bits can then be used to enlarge the pilot hole to the size hole you would like for your design. When using any rotary tool, always wear eye protection and a dust mask. The metal may become hot from the friction of the drill bit so work in small amounts of time as well as keep a piece of scrap leather handy for holding the tube. Regardless of the tools you choose to use, while working, be sure to support the tube bead on a sturdy work surface. A bench-pin clamped to your work table is the ideal tool for this task.