Steel Library/SK5 / SK85
Carbon Steel
Beginner Friendly
Budget

SK5 / SK85

Heat Treatment Specifications

Austenitizing

Temperature780°C(1436°F)
Soak Time10 minutes

Tempering

Temperature180°C(356°F)
Time60 minutes
Cycles1x

Quench Medium

water

Target Hardness

59 - 63 HRC

Performance Characteristics

Toughness7/10
Edge Retention6.5/10
Corrosion Resistance1/10
Ease of Sharpening6/10
Overall Score20.5/40

Interesting Facts

  • 1Japanese carbon tool steel (Steel Kougu = Tool Steel)
  • 2SK85 is new JIS name, SK5 still widely used
  • 3Hitachi makes SK steels - least expensive of their carbon line
  • 4Lower number = fewer impurities (SK3 purer than SK5)
  • 5Popular for industrial knives, saws, chisels

Famous Uses

Cold Steel SRK SK5
Cold Steel Recon Tanto SK5
Ontario Blackbird SK5

Best For

Traditional Japanese tools
Woodworking chisels
Hand planes
Cutlery

Similar Steels

1084

American equivalent

Aogami #2

Premium version

Not Recommended For

  • Wet environments
  • Western markets (unfamiliar)

Expert Tips

  • 1JIS version requires rust prevention
  • 2Excellent edge-holding with manageable hardening
  • 3Suitable for hand forging

Track Your SK5 / SK85 Heat Treats

Start logging your heat treatment cycles with SK5 / SK85. Track what works, compare results, and repeat your best blades.

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