How are these different from regular nut files?

The diamond coating is shaped to match a string's profile, so each stroke cuts a rounded bottom with straight sides at once. Toothed files cut a flat-bottomed slot and can drift off line.

Do they cut on both strokes?

Yes. They cut on push and pull strokes, which speeds up slotting compared with files that only cut one way.

What materials can they cut?

Bone, Corian, fossilized ivory, brass and zinc. The diamond coating is what lets them cut hard materials like bone and brass.

Will the diamond coating wear out?

StewMac says the diamond-coated files won't go dull. Diamond grit is harder than the nut materials they are made for.

Do I need a file for each string gauge?

Yes. Each file matches one string gauge, so you need the sizes that cover the strings on the guitar you are working on.

Are they worth it for a hobbyist?

Buyers call them an investment. If you slot nuts only occasionally, the cost is the main drawback; for regular work, the speed and accuracy are the payoff.

Where is the StewMac DiamondCut Nut Slotting Files cheapest?

At Amazon, for $40.19, 54% under what the other stores charge, as of our latest check.

What do buyers say about the StewMac DiamondCut Nut Slotting Files?

Rated 4.8 out of 5 from 15 ratings. Buyers like: Cut faster and more accurately than traditional toothed files; Made slotting a blank nut much faster; Worth the expense as an investment. Common complaints: On the expensive side.

Where can I buy the StewMac DiamondCut Nut Slotting Files?

5 stores we checked sell it, including Stewmac, Amazon, StewMac.com, Reverb, eBay.

StewMac DiamondCut Nut Slotting Files Price History: $40.19 at Amazon

What reviewers say

4.8 / 515 ratings

Buyers rate these files very highly. They say the files cut faster and more accurately than traditional toothed files and made slotting a blank nut much quicker. The main complaint is the cost, which buyers still call worth it as an investment.

What people mention

Cutting speedPraisedBuyers say the files cut faster than traditional toothed nut files.
AccuracyPraisedBuyers report straighter, more accurate slots than they get from toothed files.
Nut blank workPraisedSlotting a blank nut goes much faster with these files.
CostCriticisedBuyers find them expensive, though several call them worth it as an investment.

From StewMac.com

Industrial diamond-coated nut slotting files that won't go dull
Diamond coating matches the rounded string shape: rounded bottom and straight sides cut at once
Evenly distributed diamond particles cut a smooth slot without chatter or tool marks
Cut on push and pull strokes, doubling cutting speed
Don't drift like toothed files, so slots stay straight for better sound, intonation and playability
Cut through bone, Corian, fossilized ivory, brass and zinc

Materials: Industrial diamond coating
Sizing: Grit varies by width: 0.010" and 0.013" are 400-grit, 0.016" and 0.020" are 300-grit, and 0.024"–0.056" are 150-grit.
Guarantee: Backed by StewMac's lifetime promise.

About the StewMac DiamondCut Nut Slotting Files

StewMac DiamondCut Nut Slotting Files cut string slots with a rounded bottom and straight sides in a single pass. The files are coated with industrial diamond, which matches the rounded shape of a string.

The diamond particles are evenly distributed, so the files cut a smooth slot without chatter or tool marks. They cut on both the push and pull strokes, which doubles cutting speed. Unlike toothed files, they don't drift, so slots stay straight for better sound, intonation and playability.

The files cut through bone, Corian, fossilized ivory, brass and zinc. The diamond coating won't go dull.

Coating: Industrial diamond
Cuts: Bone, Corian, fossilized ivory, brass, zinc
Slot shape: Rounded bottom, straight sides
Cutting action: Push and pull strokes
Grit: 0.010" and 0.013": 400-grit; 0.016" and 0.020": 300-grit; 0.024"–0.056": 150-grit