Filing Buttons

摘要

Filing buttons are a simple, yet astoundingly useful aid to hand shaping components. They are just round discs of metal fitted either side of a hole to guide hand filing and the production of a neat, round end. For a rough and ready result, just using a cap screw or cheesehead screw might be sufficient, see photo 1, but it is very easy to get excellent results with a little more care. Obviously to get a really good result the button should be exactly the same width as the bar, and the bolt that holds buttons and bar together must be a good fit in all three parts. This is not hard to achieve, even if using a plain screw to hold the parts - but do measure the screw first. Many screws {especially metric ones) are significantly smaller than their nominal top diameter. I prefer to make filing buttons from silver steel, hardened but not tempered. Glass-hard, the file skids off them without damage, and they don't need to be left free to rotate. You can use softer materials, but if you do they need to be able to rotate so the file doesn't wear them away; this means a sloppy fit at the expense of a little accuracy. If you don't have material of the correct diameter just turn some down, the surface finish is not critical. Drill through a good snug fit for the securing screw, and part off two slices. These should not be too thin, like washers, instead aim for similar proportions to a full nut. Use the same drill on the component to be shaped - you can enlarge the hole to a larger size later if required.