Heat Treatment Specifications
Austenitizing
Temperature815°C(1499°F)
Soak Time15 minutes
Tempering
Temperature175°C(347°F)
Time120 minutes
Cycles2x
Quench Medium
oil_fast
Target Hardness
64 - 66 HRC
Performance Characteristics
Toughness3.5/10
Edge Retention7.5/10
Corrosion Resistance1.5/10
Ease of Sharpening3/10
Overall Score15.5/40
Interesting Facts
- 1Named for blue paper wrapping at Hitachi factory
- 2Contains tungsten and chromium added to Shirogami
- 3Only master blacksmiths forge this - high crack risk
- 4Rooted in 800+ years of Japanese swordsmithing tradition
Famous Uses
High-end Japanese kitchen knives
Sashimi knives
Best For
Professional kitchen knives
Cleavers
Debas
Thin-edged cutting tools
Kitchen cleavers
Deba knives
Chinese cleavers
Professional cutting tools
Similar Steels
Not Recommended For
- Wet environments (rusts instantly)
- Beginner cooks (requires care)
- Lazy owners
Expert Tips
- 1Highest wear resistance in Aogami family
- 2Prone to corrosion without care
- 361-65 HRC achievable
- 4Requires careful maintenance
- 5Achieves 61-65 HRC
- 6Excellent edge holding with thin edges (10° per side)
- 7Lower toughness relative to wear resistance