Heat Treatment Specifications
Austenitizing
Temperature790°C(1454°F)
Soak Time10 minutes
Tempering
Temperature175°C(347°F)
Time60 minutes
Cycles1x
Quench Medium
water
Target Hardness
62 - 64 HRC
Performance Characteristics
Toughness6/10
Edge Retention7/10
Corrosion Resistance0.5/10
Ease of Sharpening7.5/10
Overall Score21/40
Interesting Facts
- 1Highest carbon SK steel (~1.05% C)
- 2Used in traditional Japanese woodworking tools
- 3Hitachi SK series from least to most carbon: SK7, SK5, SK4, SK3
- 4Takes very keen edge but requires maintenance
Famous Uses
Japanese hand tools
Chisels
Plane blades
Best For
Japanese kitchen knives
Chisels
Hand tools
Similar Steels
W1
American equivalent
Shirogami #1
Premium version
Not Recommended For
- Wet environments
- Western markets
- Beginners
Expert Tips
- 1High carbon content
- 2Multiple manufacturer variants
- 3Excellent sharpness potential
- 4Rust prone - needs care