Hitachi's faithful twin of an American classic: the steel that defined premium knives for two decades.
ATS-34
For the Newcomer
ATS-34 is historically important: when Crucible temporarily stopped making 154CM in the 1970s, Hitachi developed an essentially identical alloy. The two are so close the knife community treats them as interchangeable. Both have been largely superseded by newer alloys, but ATS-34 still appears in knives from makers who value a deeply proven, mature steel. Think of it as the seasoned veteran: not the newest or flashiest, but deeply trusted with a rich track record.
About this composition
Conventional vs. PM: Same alloy, different manufacturing. This is an Steel poured and solidified as a single large block (ingot) and then forged down, the traditional non-powder process. steel rather than a A process that atomizes molten steel into a fine powder before pressing it into a billet, producing very fine, evenly distributed carbides. one, which leaves larger, less uniform Microscopic hard particles within steel that resist wear. Their size limits how fine an edge can get, so smaller carbides allow a keener, more durable apex. than CPM-154, and that means slightly less toughness and slightly less consistent performance. The difference is subtle; both are excellent steels by most practical standards.
Historical context: ATS-34 was the choice steel for top American custom makers throughout the 1980s and 90s (Bob Loveless, Chris Reeve, and many others). Its remaining culinary foothold today is Japanese artisan smiths who value its fine carbide structure and achievable 63–64 HRC hardness.
Performance Deep Dive
Edge retention: Very good.
Excellent at 60+ Rockwell C, the standard hardness scale for blade steel. Most kitchen knives fall between about 56 and 66. with quality heat treatment.
Toughness: Good.
Slightly less than CPM-154 due to the conventional carbide structure.
Research Notes
ATS-34 is primarily associated with EDC and folding knives. Kitchen examples are scarce, and no current American artisan kitchen makers use ATS-34 as a primary culinary steel. The steel peaked in American custom popularity in the 1980s through 2000s (the Bob Loveless era) and has been largely replaced by S35VN and CPM MagnaCut for new American work.
In the Kitchen
If you encounter ATS-34 on a kitchen knife today, it is almost certainly a Japanese-smith warikomi or Damascus construction running 63–64 HRC. That is a different proposition than the 1990s Loveless and Reeve folders the steel is famous for: with this steel, the artisan handling is what makes it sing. Pair it with thin Western-profile gyutos or a santoku, and follow standard stainless care.
Composition
| Element | % | Role |
|---|---|---|
| Carbon (C) | 1.05 | Hardness driver |
| Chromium (Cr) | 14 | Corrosion resistance and carbide formation |
| Molybdenum (Mo) | 4 | Toughness, hardenability, corrosion resistance |
Steel family: Conventional melt equivalent of 154CM. Same chemistry as CPM-154 and 154CM with a different manufacturing process; the larger, less uniform carbides of the conventional version translate to slightly less toughness and slightly less consistency than the powder version.
Artisan Makers
| Maker | Knife | Style | Price | Link |
|---|---|---|---|---|
| Kisuke Manaka | ATS-34 Tsuchime Gyuto 210mm | Wa-gyuto, ATS-34 core/stainless clad (warikomi), 63–64 HRC | ~$577 | knifewear.com |
| Kisuke Manaka | ATS-34 Tsuchime Gyuto 240mm | Wa-gyuto, same construction, 240mm | ~$662 | knifewear.com |
| Tsukasa Hinoura | ATS-34 Damascus Santoku 170mm | Japanese santoku, hand-forged ATS-34 Damascus, red sandalwood handle | ~$660 | japanesechefsknife.com |