Mini diamond file


Best compact durable file

[Cool Tools has a YouTube channel with many more tool reviews]

This mini diamond file runs around $10. It was recommended to us by Lenore Edman from Evil Mad Scientist, and if you pick one up using the link in the description you’re helping to support my videos and the Cool Tools blog.

You can see from the packaging here that this is intended for sharpening the edges of skis or snowboards. I can’t speak to that, but I can tell you that it is a great, compact, and durable file for all kinds of applications.

The manufacturer, DMT, does most of their business selling larger diamond whetstones for sharpening knives and tools. This is that same product on a smaller scale.

The face of the file has this polkadot pattern. The red is from the plastic backing showing through. Those holes are just slightly recessed and provide a place for little bits to collect as you file things down. The color is also there to indicate which grit you’re working with. This red one is considered Fine — around 600 grit if I understand it right. Lenore had been using the blue, coarse version, which might be better for some applications.

Now the metal part is where the magic is. You can’t tell from looking at it, but there’s a layer of industrial diamonds embedded in the metal surface. The metal is actually electro-formed around the diamonds, so it holds up to repeated use.

The back is just plastic, stamped by the manufacturer, showing that this is made in Marlborough, Massachusetts.

Because diamonds are so incredibly hard, they work as an abrasive on just about anything. You can file your fingernails, sharpen small metal tools, knives, and generally just knock the edges off anything you throw at it. It can be used wet or dry.

And because it’s not all stabby like a traditional metal file, you can travel with this without raising any eyebrows with TSA. Plus, how cool is it to have a tool made of diamonds?

-- Donald Bell 03/17/22

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