Topic · hagane
Steel and hardness
Hardness is measured on the Rockwell C scale (HRC). German stainless sits around HRC 56 to 58, VG-10 around 60 to 61, SG2 around 62 to 64. Harder steel holds a thin edge longer but chips more easily and takes longer to sharpen. Carbon steels such as Shirogami and Aogami get very sharp but rust if left wet.
- Soft and forgiving
- X50CrMoV15, HRC 56 to 58
- Hard and keen
- SG2, HRC 62 to 64; Aogami Super, HRC 63 to 65
Stainless steels such as VG-10, VG-MAX, SG2 and Cromova 18 have enough chromium to resist rust in a home kitchen. Hand wash and dry them and they stay clean. Carbon steels such as Shirogami (white paper) and Aogami (blue paper) have little chromium. They take a very fine edge and are easy to sharpen, but they rust if left wet and build a gray or blue patina with use.
Many carbon knives are clad: a hard carbon core is wrapped in softer stainless. Only the edge then needs carbon steel care, but the edge still rusts if left wet.
Hardness is a trade. Each step up the scale means a thin edge can last longer between sharpenings, but the edge also becomes more brittle. Use the steel chart to compare steels by hardness, rust risk and care.
- Edge retention
- rises with hardness
- Chip risk
- rises with hardness
- Ease of sharpening
- falls with hardness
Steels on the chart: X50CrMoV15 HRC 56 to 58; Cromova 18 HRC 56 to 58; AUS-10 HRC 59 to 60; VG-10 HRC 60 to 61; VG-MAX HRC 60 to 61; FC61 HRC 61 to 61; Ginsan (Silver 3) HRC 60 to 61; SG2 / R2 HRC 62 to 64; ZDP-189 HRC 64 to 66; Shirogami 1 and 2 HRC 61 to 64; Aogami 1 and 2 HRC 61 to 64; Aogami Super HRC 63 to 65.
Common mistakes
- Buying carbon steel when you leave knives in the sink.
- Expecting a HRC 63 blade to survive twisting cuts through squash or bone.
- Reading hardness as quality: a well heat treated HRC 58 knife can serve a home cook better than a brittle HRC 64 one.
Pages on this topic
- Why are Japanese knives so sharpJapanese knives are sharp because of harder steel, thinner blades and more acute edge angles. Learn how each factor works and the trade-offs that come with them.
- What is VG-10 steel and is it goodVG-10 is a Japanese stainless steel with cobalt and vanadium, usually hardened to about HRC 60-61. See why so many Damascus kitchen knives use a VG-10 core.
- What HRC means for a kitchen knifeHRC is the Rockwell C hardness of knife steel. Learn what the numbers mean for edge retention, chipping and sharpening, and what range suits home cooks.
- VG-10 vs SG2 steel for kitchen knivesVG-10 vs SG2 (R2): HRC 60-61 against HRC 62-64. Compare edge retention, chipping, sharpening effort and price for Japanese kitchen knives in these two steels.
- Japanese vs German knives: hardness, angle and feelJapanese knives run HRC 60+ with thin 10 to 16 degree edges; German knives run about HRC 56-58 at 14 to 15 degrees. See how that changes cutting and upkeep.
- Japanese knife steel chart: HRC, edge retention and rustA reference chart of VG-10, SG2, Aogami, Shirogami, Ginsan and German knife steels with typical hardness, rust resistance, sharpening ease and care.
- Is Damascus steel better for kitchen knivesDamascus kitchen knives are layered cladding around a core steel. The pattern looks good, but the core steel decides how the knife cuts. How to read a listing.
- Carbon steel vs stainless Japanese knivesCarbon steel vs stainless Japanese knives: sharpness, edge feel, rust and patina, what stainless clad and semi-stainless mean, and which suits your kitchen.
- Aogami (blue) and Shirogami (white) steel explainedAogami (blue) and Shirogami (white) are Japanese carbon knife steels. Compare grades, hardness, sharpening feel and rust care, including Aogami Super.
Gear for this topic
- Best high-end Japanese knives worth the moneyEight Japanese knives from $300 up compared by core steel, HRC, length, edge angle and handle: Miyabi, Masamoto, Shun, Yoshihiro and Misono.
- Best Damascus Japanese knives, judged by the core steelDamascus-clad Japanese chef knives from Miyabi, Shun, Yoshihiro and Sakai Takayuki compared by core steel, layers, hardness, length, edge angle and handle.
- Best carbon steel Japanese knivesSeven carbon steel Japanese knives compared by steel type, hardness, blade length, cladding and handle, from Masamoto, Yoshihiro and Misono.