Japanese Whetstones for Beginners: Which Grit Do You Need First?
Researched. This guide is based on instructions published by Japanese whetstone makers (Naniwa, Shapton) and knife makers (KAI, Tojiro, Global, Jikko, Sakai Ichimonji Mitsuhide), checked on October 3, 2026. We have not tested these stones ourselves. This article contains no affiliate links.
If you own a Japanese knife, sooner or later it will need sharpening. Whetstone listings are full of numbers like #220, #1000 and #6000. This guide explains what those numbers mean and what the makers themselves suggest for a first stone.
The short version
- Lower grit numbers are coarser; higher numbers are finer.
- Makers suggest starting with one medium stone, around #1000. Tojiro and Global say a medium stone is enough for home use; Sakai Ichimonji Mitsuhide says to start with one.
- Coarse stones are for repairing chips; finishing stones refine the edge. Some makers say home users rarely need them; others say a coarse stone will eventually be needed.
- Soaking depends on the stone. Some must be soaked; others should not be. Follow your stone maker’s instructions.
How grit numbers work
Naniwa, a Japanese whetstone maker, explains that grit is written as # followed by a number, and that a lower number means a coarser stone. Japanese makers group stones into three types: coarse (arato), medium (nakato) and finishing (shiageto). The exact ranges differ by source.
| Source | Coarse | Medium | Finishing |
|---|---|---|---|
| Sakai Ichimonji Mitsuhide | #80–#400 | around #1000 | #2000 and up |
| Tojiro | #80–#400 | #600–#2000 | #3000–#6000 (super-finish #8000 and up) |
| Matsunaga Toishi (King stone seller) | #80–400 | #700–1200 | #3000–8000 |
| Global (Yoshikin) | #200–#600 | around #1000 | #4000 and up |
| Naniwa (for home knives) | about #200–#400 | about #1000 | #3000–#4000 |
Notice that #2000 is a finishing stone for one source and a medium stone for another. The labels are a guide, not a standard.
What each type is for
- Coarse: Naniwa, Tojiro and Global describe coarse stones as for chipped edges and major reshaping. Tojiro says they are rarely needed otherwise.
- Medium: the everyday stone. Tojiro says a medium stone is enough for home use, and Sakai Ichimonji Mitsuhide calls it the baseline for all sharpening.
- Finishing: removes the scratches left by the medium stone and refines the edge. Tojiro warns that jumping more than about #3000 in one step makes the earlier scratches hard to remove.
Which stone to buy first
These are the makers’ suggestions, not ours.
- Tojiro: one medium stone of about #1000 is enough to start.
- Global: a medium stone is enough for home use.
- Sakai Ichimonji Mitsuhide: start with a medium stone, then add coarse and finishing stones later.
- Shapton, a whetstone maker: for household knives, it suggests its #1000 and #5000 stones from the Kuromaku line, or its #1500 if you buy only one.
- Naniwa: markets its BASE line for first-time buyers, in #220/#1000 and #1000/#3000 combinations.
To soak or not to soak
Makers disagree here because their stones are made differently.
- Shapton says its stones need no soaking, though it suggests an optional 5–6 minute soak before first use. It warns against soaking them for 30 minutes or more because the stone softens.
- Naniwa names some of its lines as no-soak stones that you simply wet, and tells you to soak its BASE stones for about 10 minutes.
- KAI tells you to soak ordinary synthetic stones until the bubbles stop, roughly 10–20 minutes. Jikko says 5–10 minutes and Global about 20 minutes.
The safe rule: read the instructions that came with your stone.
Flattening the stone
Stones wear unevenly and develop a dip in the middle. Naniwa says a concave stone cannot produce a sharp edge, and KAI says the dip makes the sharpening angle unstable. Shapton recommends flattening before every sharpening session.
Makers disagree on how to flatten. Matsunaga Toishi suggests a flattening stone or coarse waterproof sandpaper, while Shapton warns that sandpaper can clog the surface of its stones. Use the method your stone’s maker recommends.
Sharpening angle
- KAI: about 15° per side for a double-bevel knife.
- Global: about 15°, roughly the height of one or two stacked 10-yen coins under the spine.
- Jikko: raise the spine the height of one or two 10-yen coins.
- Tojiro: gives no number; it says to keep the knife’s existing factory angle, and that sharpening more acutely than the maker’s angle may void the warranty.
You will also see makers say to hold the knife at about 45° to the stone. That refers to the knife’s direction across the stone seen from above, not the edge angle.
Caring for the stone, and staying safe
- Shapton: do not use hot water, which can crack the stone; do not dry it with a fan or put it in a dishwasher.
- Tojiro: rinse the stone, let it air-dry and store it in the shade; leaving it wet for long periods can damage it.
- Jikko: an unstable stone is very dangerous, so make sure it cannot slide while you sharpen.
- Global warns that you can scrape your fingertips on the stone.
Sharpening involves a very sharp blade. Follow the knife and stone makers’ instructions, work slowly, and keep fingers clear of the edge. If your knife is expensive or you are unsure, consider a professional sharpening service. See our Terms of Use & Disclaimer.
Related: Japanese Knife Steels Explained covers why some steels are harder to sharpen than others, and How to Care for a Japanese Kitchen Knife covers everyday care.
Sources
- Naniwa: FAQ (Japanese)
- Naniwa: whetstone lineup (Japanese)
- Naniwa: Honshoku Super Ceramics stones (Japanese)
- Naniwa: BASE series (Japanese)
- Naniwa: flattening (Japanese)
- Shapton: FAQ (Japanese)
- Sakai Ichimonji Mitsuhide: whetstone grit (Japanese)
- Tojiro: choosing a whetstone (Japanese)
- Tojiro: sharpening basics (Japanese)
- Tojiro: whetstone care (Japanese)
- Matsunaga Toishi: whetstone tips (Japanese)
- Global (Yoshikin): knife care (Japanese)
- KAI: sharpening a double-bevel knife (Japanese)
- Jikko: sharpening a double-bevel knife (Japanese)
- Jikko: whetstone maintenance (Japanese)
We check facts against the sources above, as described in our Editorial & Accuracy Policy. If you spot an error, please tell us through our contact form.
