How to Sharpen Your Knife With a DiaFold Diamond Sharpener
By Half Face Blades | tools that cut deep | Published: 2026-10-31
Category: How-to Guides
A practical, field-ready process for sharpening a fixed blade knife with the DMT DiaFold double-sided diamond sharpener, including angle control and common mistakes.
Quick answer
Sharpen on the DiaFold's fine side first to raise a burr along the full edge, then switch to the extra fine side for a few light passes to refine it. Keep the blade at a consistent angle, use light pressure, and work in one direction per stroke; no oil or water is needed.
Why the DiaFold suits fixed blades in the field
A fixed blade often needs attention away from a bench, and the DiaFold's folding handle protects the diamond surface in a pack while giving you a rigid base to hold. Because it cuts with diamond abrasive rather than a stone that loads up, it keeps working on harder steels without oil or water.
The trade-off is that the two faces are narrow and short compared with a bench stone. That makes angle control more demanding on long blades, so slow, deliberate strokes matter more than speed.
Match the face to the job, not to habit
The red fine face (25 micron / 600 mesh) is the working surface for dull or damaged edges; the green extra fine face (9 micron / 1200 mesh) is for finishing and touch-ups. Starting on extra fine when the edge is already blunt wastes time and can glaze over the real problem.
If you are unsure which face you need, test the edge first: if it slides on your thumbnail or catches light, begin on fine. If it already bites, a few extra fine passes may be all that is required.
Angle control is the skill to practice
The DiaFold does not set an angle for you, so your consistency decides the result. Pick an angle that matches the blade's intended use and keep it fixed; a common field approach is to lay the blade flat and lift the spine until you feel the bevel sit on the diamond, then hold that relationship through every stroke.
Check your angle by watching the scratch pattern: if it spreads up the bevel, you are lifting the spine too far. If it stays only at the very edge, you are too shallow.
Step-by-step: sharpening a fixed blade with the DiaFold
- Set up and inspect the edge: Open the DiaFold and hold it securely on a stable surface or in your hand. Look along the edge under light to find nicks, flat spots, or a rolled section before you start. Mark the damaged area mentally so you can give it extra attention without over-grinding the rest of the edge.
- Choose the fine face for dull edges: Start on the red fine face unless the edge only needs a touch-up. Place the blade at your chosen angle and make slow, controlled strokes, moving from heel to tip on one side. Common mistake: rushing with heavy pressure. Let the diamond cut; pressing harder rounds the edge instead of sharpening it.
- Work one side until you feel a burr: Continue on the same side with consistent strokes until you can feel a slight burr along the full length of the opposite edge. Keep the angle steady and check the burr at the heel, middle, and tip. If the burr appears only in one spot, you are rocking the blade; reset your angle and use shorter strokes.
- Repeat on the other side: Flip the blade and match the angle on the second side, working until the burr is felt along the first side. Count your strokes if it helps you keep both sides even. Uneven burrs mean an uneven edge; aim for the same burr size on both sides before refining.
- Refine on the extra fine face: Switch to the green extra fine face and make a few light alternating passes per side at the same angle. Use less pressure than on the fine face and stop when the edge feels smooth and bites consistently. Do not polish for its own sake; a few passes preserve the toothy working edge a fixed blade often needs.
- Remove the burr and test: Make a few very light passes on the extra fine face, alternating sides, to weaken the burr. Test by slicing paper or shaving a small patch of hair on your arm, then strop on your pants leg or a leather belt if available. A wire edge that bends rather than cuts means you need a few more light alternating passes, not more pressure.
- Fold, clean, and store: Wipe the diamond faces with a damp cloth or brush to remove steel particles, let the tool dry, and fold the handles closed. Store it away from loose items that could dull the diamond surface. Checkpoint: a clean diamond face cuts more consistently next time; skip this and the tool glazes over faster.
Product facts
- DiaFold Double Sided Diamond Sharpener FINE/Extra FINE: Double-sided diamond sharpener with fine (25 micron / 600 mesh) and extra fine (9 micron / 1200 mesh) faces. One tool covers edge repair and refinement, so you can carry less in a field sharpening kit.
DiaFold Double Sided Diamond Sharpener FINE/Extra FINE - DiaFold Double Sided Diamond Sharpener FINE/Extra FINE: No oil or water is needed, and the handles fold for storage. You can sharpen dry and pack the tool away without a mess, which suits fixed blades used outdoors.
