All You Ever Wanted to Know About Diamond Files and How To Use Them

What is a Diamond File?

Diamond Files are manufactured by electroplating diamond onto steel blanks using nickel. The smaller the particles, the finer the grit of the file. This is why diamond files are referred to in grits rather like sandpaper. The higher the number, the smaller the grit and the finer the finish. For example, a 600 grit diamond file will be much finer than a 220 grit.

Why Use a Diamond File instead of a Traditional Steel File?

As you know traditional steel files have teeth rather like a saw blade. The smaller the teeth, the finer the cut of the file, but all these teeth are lined up in the same direction. So this means that with a traditional file, it will only cut in one direction like a saw. Even when you have a round or half round file, they still only cut in a forward direction. They don't work sideways or in a circular motion, for example.

In contrast, diamond files don't actually have teeth as such, but diamond grit. This gives diamond files a unique property in that they will work in any direction.

Advantages of using a diamond file over a steel file.

Diamond Files cut in all directions, produce a better finish

The distribution of diamond particles enables the diamond needle file to not only cut in all directions but also produce a much better finish. Therefore diamond needle files can offer a fantastic abrasive for a variety of applications.

Due to the hardness of diamonds, diamond files can be used on a variety of materials that other abrasives will not have an impact upon.

Diamond files cut in all directions and cut on the push stroke as well as the pull stroke

Diamond Files cut on the pull stroke as well as the push stroke

When you're working in small intricate areas the diamond file will work on the pull stroke just as effectively as it does on the push stroke. So this may make it slightly easier in confined spaces. It also means in theory that it will cut twice as fast as a toothed file of the same grit because it's cutting on the pull as well as on the push stroke.

Another huge advantage is the fact that they also work sideways and with a twisting motion.

How to Use Diamond Files

1. Use the tip of a diamond file for detailed areas such as ring shanks

You can use the fine tiny points of the files to get into tiny areas. As long as you can move the file in any direction, it will cut and it will file for you. This is particularly useful with a large round 600 grit diamond file or a 600 grit diamond needle file as it can be rotated inside a hole or outside a ring, and it will cut in 360 degrees.

Great for the inside of ring shanks and also for deep burring. A diamond needle file in a half round shape, 220 grit is also great for the inside of rings and bangles and it has a nice wide flat profile so that can be used on the outside of rings without changing files. A great companion to the 600 round file.

Half round 220 grit large diamond file for the inside and outside of ring shanks

600 grit large triangle diamond file ideal for intricate areas and removing solder

2. Sharpening carbide cutting tools

Over time tungsten carbide cutting tools will dull and it is often easier to have a hand tool abrasive that you can take straight to the cutting tool, rather than having to take a cutting tool to an electric grinding wheel. 600 grit diamond files are the best grade for this application on tungsten carbide.

3. Enlarging holes

A round diamond needle file can be used for opening up a huge array of holes in hardened surfaces, 600 grit being the most common for most applications. Small screw holes in watches and clocks to holes in jewels and beads can all be opened up with a round diamond file. Choose diamond files that are either 600 or 900 grit for the best results.

4. Removing excess solder

If you solder a post onto the back of an earring, for example, a square 600 grit diamond file will help you get right into that solid joint and clean up both the horizontal and vertical surfaces. It also has a very nice sharp point. A round diamond file can be used for removing excessive solder inside a ring band and the finish is finer than what you would achieve with a traditional ring file.

Squre 600 grit diamond neede file used for removing solder

5. Fitting clock and watch glasses

Sometimes, the sizes need to be altered slightly when fitting watch or clock crystals. Using a 600-grit diamond needle file will produce the required result in minimal time.

6. Refacing clock & watch pallets

Clock and watch pallets are very hard and become burred and misshapen over time. Using a 900 grit fine diamond file can radically change the surface of the pallet for a more efficient movement.

Taylor horology using a 900 grit square diamond needle file

The above image shows Brad Taylor of using a 900 grit small square diamond file

7. Shaping precious stones for jewellery

Precious stones can be extremely hard, especially quartz, sapphire and ruby, and small alterations may be required when setting stones into jewellery. No other abrasive will have such an effective impact as a diamond needle file. Fine grades such as 600 and 900 grit are ideal for making these small adjustments. Try a small flat 600 grit file, or a small half round 900 grit for superfine finishes.

small half round for shaping cabochons and precious stones

Lucylou designs uses a diamond file to shape and smooth her cabochons, as seen above.

8. Repivoting clock and watches

Removing the burrs and wear from pivots is often tricky due to their hardness, especially in French clocks. The use of a 600 grit diamond needle file can have the pivot running smoothly in no time at all.

9. Bevelling cut crystal glasses and filing glass

We all know it is easy to chip the rim of your precious crystal glass, and due to the cost of replacing one in a set, using a diamond needle file can be far more economical to bevel the lip of the glass. It is essential that a 600 grit diamond file is used and a half round shape is by far the most versatile for the contour of the glass.

The above image shows a glass bottle that has been cut, the edges of which are being filed down with a large square 600 grit diamond file.

Small 600 grit files are great for filing the edges of mosaic pieces as well

10. Sharpening household objects

Scissors, penknives, garden tools, kitchen knives, small screwdrivers, and guitar and violin strings can all be sharpened to a razor-sharp finish in very little time. You can use various sizes of diamond file for this application but a 600 grit is recommended.

11. Cross-graining burnishing tools

Over time, burnishing tools lose their burnishing ability. Only diamond files can re-address the cross grain of a sapphire burnisher or hardened steel burnisher. Opt for the 600 grit for the best results.

12. Sharpening fishing hooks and ice screws for winter climbing

One of the most important tools of an angler has to be his hook, and in carp fishing in particular, this has to be razor sharp (sticky sharp). The use of a Flat 600 grit diamond needle file is ideal for this due to its size and profile. It is essential that the very hard-to-find diamond escapement file is used for this operation; this allows dexterous filing all around the hook point.

How to Clean Diamond Files

Always use your diamond files wet where possible, as this will help prevent debris from becoming lodged in the diamond grit. If you still find material clogging up your diamond file, you can try any number of the following:

  1. mild soap and a bristle brush (i.e. a toothbrush)
  2. brass or steel bristle wheels run in a rotary tool
  3. aluminium oxide or soapstone - rub the file across the surface

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