A common buyer question: "diamond stone or ceramic rod — which one?" Engineer Yanchi Li (Ruimo Tech) put two Sy Tools tools — the D-series diamond stones and the YHB ceramic rod — against the same edge and measured the behaviour. No "5 out of 5 stars" — only what shows under the loupe and on the cut.
Method (honestly)
We used one German chef's knife (~56 HRC) and one Japanese blade (60+ HRC). After each session we inspected the micro-geometry and tested paper and tomato cuts. Micron-level removal varies knife to knife, so we describe it qualitatively without invented ratings.
Comparison results
| Criterion | Sy Tools D-series (diamond) | Sy Tools YHB (ceramic) |
|---|---|---|
| Metal removal | High — rebuilds the angle fast | Minimal — alignment only |
| Hard 60+ HRC steel | Yes, no loading | Yes, protects thin edge |
| Edge "tooth" left | Slightly toothier | Smoother, polished |
| Care | Rinse with water | Rinse, avoid drops |
| When to use | Repair, heavy dullness | Daily upkeep |
Steel compatibility
- Soft German steel (52–58 HRC): both work; D-series restores shape faster.
- Hard Japanese (60+ HRC): YHB is preferable; RB only point-fixed with light pressure.
- Powder steels (S90V etc.): D-series handles what ceramic slips on.
Care
Rinse off metal dust after each use. The diamond D-series is long-lived and needs no flattening; the ceramic YHB is brittle — don't drop it, store separately. Line pricing is ¥4.99–14.99 (Russia retail price — 待核实).