Knife Burr: How to Find It and Remove It on a Whetstone

A knife burr is a fine lip of steel that projects beyond the cutting edge during sharpening. Also called a wire edge, it can feel like a rough catch on one face of the blade. To remove it, begin with light strokes on the stone, alternating faces, then check the full cutting length again.

Check for a burr · Remove it on a whetstone · Fix a stubborn burr

What does a knife burr look like?

Under magnification, a burr can look like a thin flap or ragged lip extending past the edge. Many burrs are too small to see clearly with unaided eyes.

The apex is the line where the bevels meet. During sharpening, steel near that line can bend away from the abrasive and remain attached beyond the intended edge. After working one bevel, check the other face for the projecting lip.

Loose metal filings are sharpening debris called swarf. They can rinse away, while a burr stays attached to the edge. A chip is a missing piece of steel, so more stropping will not repair it.

How do you check for a burr safely?

Use a cotton bud to check for a catch while keeping your skin clear of the edge.

1. Rinse off sharpening residue and dry the blade carefully. Hold the handle securely and keep the knife still.
2. On the face away from the one just sharpened, brush the cotton gently from the flat of the blade towards and just off the cutting edge. Move across the edge, never lengthways along it.
3. Check in short sections over the whole cutting length, including the heel and tip. A burr can catch or pull fibres on one face.
4. Repeat on the other face. Bright light and a magnifier can help locate a larger lip, but a reflection or snag can also come from damage.

A fingertip may sense a slight hook or roughness, but there is no need to touch the edge with bare skin. A catch is a clue. A smooth result cannot rule out a small or upright burr: Knife Steel Nerds found burrs that escaped both touch checks and paper slicing.

How do you remove a knife burr on a whetstone?

I work one side until I can feel a burr along the full edge. To remove it, begin with controlled passes into the edge, alternating faces and reducing pressure. I've checked my edges under a microscope to confirm the burr was gone and the apex was clean.

This is a practical starting method for a plain kitchen knife sharpened on both faces. Serrated knives and knives with a bevel on only one face need a different approach.

Prepare the stone according to its instructions and secure it on the bench. Match the existing bevel angle. For the full setup, use the whetstone sharpening instructions. For a flexible blade, follow the fillet knife sharpening steps.

1. Finish sharpening both bevels and check that the abrasive reaches the edge on each face. Check frequently and avoid building a large flap of steel. A burr that merely flips between faces is not enough to establish that both bevels are finished.
2. Make a gentle pass with the cutting edge leading into the stroke. This is the direction used when taking a thin slice, but keep the blade gliding over the stone without digging into it.
3. Turn the knife over for the next pass. Keep the angle steady and use less pressure than during the main sharpening work. Check after a few pairs of passes.
4. If a coarse burr persists, refine the edge on a finer stone and repeat the checks. A finer abrasive can reduce the burr, but moving to a finer grit does not automatically remove it.

There is no fixed stroke count that proves the job is done. If the catch keeps moving between faces, inspect the edge before adding more passes.

A combination stone provides both sharpening and finishing surfaces. The 1000/6000 Whetstone with Bamboo Base has a 1000 grit face for sharpening and a 6000 grit face for finer finishing. Keep checking for a burr on both grits. Other grit combinations are in the whetstone collection.

Do you need a leather strop to remove a burr?

A strop is optional. Deburring can be done on a stone, and stropping is a possible finishing step after the main stone work. My own sharpening kit includes strops in six different micron grades.

If using leather, move the knife with its spine leading and the cutting edge trailing behind. Keep a steady angle and gentle pressure. Pushing the edge into leather can cut the strop. Pressing hard into a soft surface risks rounding the edge.

The Vegetable Tan Leather Double Sided Strop includes a side loaded with abrasive compound. The leather strop technique guide explains the motion. Check again afterwards, since a smoother feel alone does not establish that the burr is gone.

Why won't the burr go away?

A persistent catch can mean the burr is being bent between faces or that the abrasive is not removing it.

• If the catch swaps faces with each pass, stop repeating long sets of strokes. Check angle control and try a finer abrasive.
• If very light strokes make no progress, the stone may not be cutting at that pressure. Avoid simply pressing harder. Check that its surface is flat and clean, following its maintenance instructions.
• If paper always snags at one spot, inspect that section for a chip or an area that has not reached a clean edge. Treating the whole blade again can remove steel unnecessarily.
• If the knife cuts well briefly and then loses its bite, a remaining burr may have folded. Edge damage or poor angle control can produce similar symptoms, so inspect before starting again.

How do you know when to stop deburring?

Stop when the edge cuts evenly along its length and your checks no longer reveal a projecting lip on either face. These are useful home checks, rather than microscopic proof.

Slice plain paper with different parts of the edge, keeping your holding hand clear of the cutting path. Wash the knife before trying it on food. A tomato on a stable chopping board gives a useful check of how the edge starts a cut, as demonstrated in Serious Eats' whetstone guide.

If cutting remains consistent through ordinary food preparation, put the sharpening kit away. Extra passes can create more work.

Frequently asked questions

What is the burr of a knife?

It is a small projection of steel left attached at the cutting edge during sharpening. A detectable burr helps track progress, but the edge still needs finishing.

What does a knife burr feel like?

A bent burr can feel like a slight rough hook on one face. Some burrs are too small or too well aligned to feel, so use more than a touch check.

How should burrs be removed?

For a plain kitchen knife with two bevels, start with controlled strokes into the edge on a whetstone and alternate faces. Refine and recheck as needed, with stropping as an optional finishing step.

Should you hone straight after sharpening?

I never hone straight after sharpening. Finish the burr removal on the stone and check the edge. Honing is maintenance between sharpenings.

Why is there no burr when sharpening?

The abrasive may not yet be reaching the apex: colour the narrow bevel with a marker and inspect where a few strokes remove it. Ink remaining at the very edge suggests the angle or grinding needs attention. A large burr is also less likely on harder steel, as explained in Knife Steel Nerds' discussion of hardness and sharpening, so avoid grinding endlessly just to feel one.

Does a burr mean the knife is sharp?

It shows progress at the part of the edge where it formed. An attached burr can still cut, so judge the finished knife by the full edge and its behaviour in use.