A good knife, properly cared for, lasts for decades. Mistreated, even the finest knife stops cutting within a few years. In this guide, Hayashi Hardware (founded in 1872) walks you through everything from daily care to sharpening, dealing with rust, and storage.
Daily care: wash it right away, dry it right away
Three steps after every use
- Wash it right away: don't leave it sitting. Wash with running water, mild detergent and a soft sponge — especially promptly after acidic foods (citrus, tomato, pickled plum) or salty ones.
- Dry it right away: with a clean, dry towel, wipe all moisture from the blade, the handle and the ferrule (where blade meets handle).
- Let it air out before putting it away: leave it somewhere with airflow for a while before storing.
That alone makes a huge difference to a knife's life. Almost every case of rust or handle damage comes from moisture left sitting.
What never to do
| Don't | What happens |
|---|---|
| Dishwasher | Heat and detergent crack and degrade the handle and damage the blade |
| Cutting frozen food or bone | Chipping (the harder the steel, the more easily it chips) |
| Leaving it wet | Rust, darkened handle, loosened ferrule |
| Soaking in bleach | Corrosion and discoloration of the blade |
| Prying, or opening cans | Broken tip |
| Glass or stone cutting boards | Rapid wear of the edge |
| Heating over a flame | Ruins the heat treatment and the steel loses its hardness (irreversible) |
We recommend wooden or softer plastic cutting boards.
Sharpening on a whetstone: 5 steps for beginners
When the knife starts to dull (a good test: the edge slides on a tomato's skin instead of biting), sharpen it on a whetstone.
You will need: a medium whetstone (#1000) / ideally a finishing stone (#3000–#6000) / a damp towel to keep the stone from slipping
Steps
- Soak the stone: 10–15 minutes, until no more bubbles rise (for soaking-type stones).
- Set the angle: about 15 degrees between blade and stone — roughly the gap of two stacked coins under the spine.
- Sharpen with push strokes: edge facing away from you, apply pressure on the push and relax on the pull. Divide the blade into 3–4 sections and give each 20–30 strokes.
- Check for a burr: gently feel the opposite side of the edge with the pad of your finger. A slight catch (the burr) means that side is done. Repeat on the other side.
- Finish: repeat the same motion lightly on the finishing stone to remove the burr, then stroke the edge lightly across newspaper.
How often: about once a month for home use. Sharpen when it first feels a little dull rather than waiting until it stops cutting — it takes far less time.
Note: on fluorine-coated knives such as the Kurokage series, the coating at the very edge gradually wears away with sharpening (unavoidable by design). The black finish on the blade face is unaffected.
If rust appears
Even stainless knives can develop spots of rust if left wet.
- Light spots: put a little cream cleanser on a dry cloth or a wine cork and rub gently along the length of the blade.
- Wider rust: polish lightly with wet-and-dry sandpaper (around #1000), then finish with cleanser.
- Deep rust or chips: don't force it — leave it to a professional. Our resharpening service can help.
Rust left alone goes deeper. Deal with it as soon as you notice it.
Caring for wooden handles
Wooden handles — ho wood, wenge, ebony — dislike moisture just as much as the blade does.
- After washing, always dry the handle and the area around the ferrule.
- About once a month, rub in a thin coat of a food-safe drying oil (walnut or linseed oil) to keep the luster and water resistance.
- If the handle loosens or wobbles, stop using the knife and have it repaired.
Ebony and wenge grow glossier the more you use them. Watching them age is part of the pleasure.
How to store your knife
- Everyday knives: a well-ventilated knife block or stand. Ideally the blade should not touch other metal.
- In a drawer: use a blade guard (saya). Blades knocking against other utensils cause chips.
- Long-term storage: dry completely, wipe the blade with a thin coat of camellia oil, wrap in newspaper, and keep somewhere dry.
Leave it to the pros: our resharpening service
If you are not confident sharpening yourself, or the edge has chipped, use our resharpening service.
- Knives bought from us: first resharpening free (from ¥1,500 per knife after that)
- Mail-in service within Japan. Customers outside Japan, please contact us first.
- We also advise on repairing chips and handles.
Kept sharp over the years, a good knife lasts a lifetime.
Frequently asked questions
Is a pull-through sharpener good enough?
It works as a quick fix, but it creates a temporary "bite" by roughing up the edge, so heavy use shortens the blade's life. The ideal combination is a whetstone session once a month, with a sharpener only as a stopgap.
How often should I send it for professional sharpening?
If you don't sharpen at home, about once every six months to a year.
Should I oil a stainless knife?
Not for daily use. We only recommend it for long-term storage of a month or more.
Do I need to sharpen a new knife before using it?
No. The Sakai Takayuki knives we sell come with a finished edge put on by the craftsmen, ready to use.