Pull-through sharpeners aren't bad as a category. A carbide pull-through is a fast, rough tool that's fine on inexpensive knives and wrong for thin, hard ones. A ceramic or diamond pull-through set to your knife's angle is a decent way to keep a kitchen knife sharp. The real damage comes from the wrong knife in the wrong slot, or from leaning on it. The best knife sharpener for kitchen knives guide shows where pull-throughs fit next to stones and electrics. Or skip the tool and mail the knives out.
The short answer, by knife
| Your knife | Carbide slot | Ceramic slot | Diamond slot at the right angle |
|---|---|---|---|
| Cheap stamped kitchen knife, block-set steak knives | Fine | Fine | Fine |
| Utility and camp knives | Fine | Fine | Fine |
| German forged (Wüsthof, Zwilling, Henckels) | Occasionally, gently | Yes | Yes, at 14-15° |
| Victorinox Fibrox and other softer stamped steel | Fine | Yes | Yes, at 15-20° |
| Japanese double-bevel (gyuto, santoku) | No | Only at 10-15° | Only at 15° or less |
| Single-bevel Japanese (yanagiba, deba) | No | No | No |
| Serrated bread knife | Only if the maker allows it | Only if the maker allows it | Only if the maker allows it |
| Ceramic (zirconia) knife | No | No | Only a slot made for ceramic |
Most of the arguing online comes from people talking about different slots. Someone whose $15 carbide gadget chewed a Japanese knife is right. So is someone whose ceramic pull-through has kept a Victorinox sharp for ten years.
What's in the slot: carbide, ceramic or diamond
| Slot | How it removes steel | Edge it leaves | Best-selling examples |
|---|---|---|---|
| Tungsten carbide plates | Scrapes it off with hard corners | Fast, toothy, often a burr; can chatter on hard steel | AccuSharp, the coarse slot of the KitchenIQ Edge Grip, Smith's CCKS |
| Ceramic rods or wheels | Fine abrasive grinds a little | Smooth; slow on a very dull knife | Zwilling 4-Stage, the Henckels handheld, the KitchenIQ fine slot |
| Diamond-coated rods or wheels | Coarse-to-fine abrasive grinds evenly | Clean and consistent, works on hard steel | Chef'sChoice Pronto 463 (15°), Work Sharp pull-through |
| "Coarse, medium, fine" with no material named | Unknown | Unknown | Several of Amazon's top sellers; see the best sellers ranked |
Sharpening Supplies, a sharpening retailer, puts it plainly: carbide models are the aggressive ones, and "ceramic and diamond pull-through sharpeners tend to be more gentle on knives." The catch is that carbide's speed is why people like it. A carbide slot will pull a beaten-up edge back in a few strokes where a ceramic rod would take dozens.
What the one measured test found
Most pages that answer this question are written by people who sell whetstones or sharpening services. The one with numbers is Knivesandtools, a European knife retailer that dulled a chef's knife to 600 on the BESS scale (the force needed to cut a test line; lower is sharper) and ran five pull-throughs, following each maker's instructions, until the edge stopped improving.
| Sharpener | Abrasive | Result (BESS, lower is sharper) |
|---|---|---|
| Chef'sChoice ProntoPro 4643 | Diamond | 228 |
| DMT SimpleSharp | Diamond | 280 |
| Zwilling TwinSharp Select | Steel wheels, then ceramic | 288 |
| Vulkanus VG2 | Carbide, self-adjusting | 294 |
| Skerper Basic | Diamond, then ceramic | 306 |
| The same knife out of the box | 306 |
Every one matched or beat the factory edge. That's the strongest evidence that pull-throughs work. Two limits apply. The test measured sharpness on day one, not how much steel went into the sink or how the edge held up. And the only carbide model was a self-adjusting design that the testers found slow and gentle, not the fixed carbide V that dominates Amazon's best-seller list. Knivesandtools' own verdict: easy and quick, but water stones are still the choice for the sharpest edge.
What the critics get right
Outdoor Life's Drew Conover, who runs a sharpening business, lists the problems he sees on knives brought to him: a burr left on one side, a wavy "chatter" pattern near the heel from carbide blades skipping along the edge, deep gouges from pulling the knife through crooked, and fixed angles that are wider than the knife's factory edge. That's experience, not a controlled test, but every point lines up with how a carbide V works.
Chef's Armoury, an Australian Japanese-knife seller, goes further. It calls pull-throughs "detrimental to your knives" and says ceramic wheels can chip thin Japanese blades and that single-bevel knives are ruined by them. The single-bevel point is right without question: a two-sided slot grinds a bevel onto the flat back of a yanagiba or deba. The rest is a fair warning for Japanese knives and overstated for a Victorinox.
Two points the critics leave out matter just as much. Pressure is the user's fault, not the tool's: Wüsthof tells owners of its own hand-held sharpener to hold the knife perpendicular and use only the weight of the blade. And frequency: Wüsthof says its coarse carbide slot is for about once every year or two, with the fine slot or a steel in between. Used that way, even a carbide stage takes little steel over a knife's life.
A 30-second check: is yours doing damage?
- Hold the knife edge-up under a ceiling light and tilt it slowly. A sharp edge is invisible. Bright dots or lines are flat, rolled or chipped spots.
- Slice a sheet of printer paper from heel to tip. It should cut cleanly the whole way. A snag in one place means that section of edge is ragged or dull.
- Lay the edge on a flat cutting board, heel to tip. A gap near the heel means repeated pulls have ground that section away (a "recurve"), usually because a thick heel collar on a forged knife keeps the heel out of the slot.
- Look at the edge with a magnifier. An illuminated jeweler's loupe shows chatter marks as a wavy, saw-toothed line.
Bright spots that come back after every sharpening, a snag that moves around, or a heel gap that grows are signs to change tools for that knife. A burr that folds after a few cuts is a technique problem: finish with light pulls in the fine slot, then a few strokes on a honing rod.
How to use one without hurting the knife
The steps are in how to use a knife sharpener. The habits that save steel:
- Start in the fine slot. Go to the coarse slot only when the fine one stops working.
- Pull, don't saw, and keep the blade vertical. Henckels' instructions for its 2-stage sharpener call for moderate pressure in the coarse slot, up to 20 pulls depending on dullness, then 5 to 10 light pulls in the fine slot.
- Let the weight of the knife do the work in a carbide slot.
- Keep serrated knives out unless the maker allows them. Henckels' and Amazon Basics' pull-throughs rule them out; AccuSharp and KitchenIQ allow them.
- Match the angle. A 20° slot on a 15° knife grinds the whole bevel back before it reaches the edge. The knife sharpening angle chart has factory numbers by brand.
When to use something else
If your knives are Japanese, if one cost more than the sharpener by a factor of ten, or if the checks above keep failing, switch tools. A rolling sharpener holds a fixed angle with a diamond disc and no carbide. A stone like the Sharp Pebble 1000/6000 removes the least steel and works at any angle; whetstone vs knife sharpener lays out the trade-off, and sharpeners for Japanese knives lists tools that suit hard steel. Bread knives need a tapered rod; see how to sharpen a serrated knife.
If you'd rather keep a pull-through, buy one that tells you what's in it. Our best manual knife sharpener picks name the abrasive and the angle for every slot. For a mixed block, the Sharp Pebble 5 Precision Adjust lets you choose 12 to 24 degrees.
Sources: Knivesandtools pull-through sharpener test; Outdoor Life, "How to Use a Knife Sharpener (and Why You Should Avoid Pull-Through Sharpeners)" (updated March 15, 2025); Chef's Armoury, "Truth About Pull Through Knife Sharpeners"; Sharpening Supplies, "Pros and cons of pull-through sharpeners"; Henckels 2-stage sharpener instructions (henckels.com) and Wüsthof hand-held sharpener guidance (wusthof.com). All read October 21, 2026, except the Wüsthof pages (October 15). Product details from Amazon listings checked October 21. How we research · Affiliate disclosure